Ok. I will tell you a little of what I learned when I prepared for my own demise 30 December 1994. You want it this badly to beg for it, fine I will give it to you.
Just understand, I would prefer if you didn't opt out... we discussed this, but since you are bound and determined to do this, then at least I can give you some pointers to where you can actually do it, instead of end up in a semi-vegitative state by a bad mix of drugs, or because you got just enough oxygen to keep most of the brain going - not all, but most.
First of all, rarely does od'ing on just any ingested (orally) drug result in death, once you do ingest a toxic level of most drugs what happens is that as soon as the body starts absorbing it, the body revolts and turns to purging its stomach (vomiting).
While there are certain cocktails of prescription strength medications one can grind up and mix into a pudding that is slow activated,and slow to trigger a vomiting session, I seriously doubt that unless you are terminal you can get a hold of those. Even if you are terminal, most doctors take that whole 'Do not harm' oath thingy pretty damn seriously.
So what many terminal patients do is they they take a of sedatives/tranquilizers - not a lot as to die from it, but to put them in a deep, deep sleep. One can accomplish that with about 10-20 adult strength dosages of most OTC sleeping pills.
Then they take a 33 gallon trash bag, and fill it full of air, and pull it over their head then tape the opening to their neck - full of fresh air. As much fresh air as possible.
Then they lay back and let the relaxing pills take them to a deep, deep slumber.
Assuming that they have taped off the bag sufficiently air tight, assuming no one walks in on them, assuming that they took enough sleeping pills or sedatives to keep them immobile when the air runs out, they asphyxiate. The condition is called
Asphyxia.
Why do it this way? Because asphyxia is a nasty way to go. Your whole body will fight for air, so you need to get your body into such a deep sleep that the best it can do is wiggle uselessly on the bed, so you don't tear at the plastic. Worst possible thing is to get SOME brain damage and your hand rip open the bag and you get oxygen, you continue to live but at some level of vegetable, or retard, or debilitated to the point where you have to be watched all the time and never really get a second change do to it right.
Understand that as a male you will undoubtedly spring a hardon, which given your age will most likely remain stiff after your death. Meaning who ever finds you will undoubtedly wonder if this was a
sex act gone horribly wrong.
I strongly suggest you fast for at least 2 days before, and stop drinking fluids at least 12 hours before you do this. Hopefully before you do this you will have a healthy bowel movement. Trust me, when a person expires their bowels loosen, and something about death shit is particularly more unpleasant than regular living shitting.
Trust me, I walked into many a dead person's house, some of whom actually opted out in this manner. They were terminal of course so God knows that they deserved an easy out. Oh I have dealt with the ones who stuck it out to the last shuddering agonizing breath of their terminal illness, unpleasant, but not quiet as unsettling as walking in on a suicide. I don't know, just something about a person who murdered themselves just sets off alarm bells in a person's mind that dying from full blown AIDS or Cancer just doesn't do.
My option was similar to the above, however I also had some pretty power medications (I was a drug dealer at the time, I could get a hold of a lot of drugs), and I spent a considerable amount of time in the public library... The internet wasn't that well known and I had no real access to it, so I hit the books.
I doubt you are a drug dealer, so I'm not going to coach you on what cocktail to aim for. Suffice to say this option mayn't be that practical.
I came to find out after being moved out of ICU to the mental health ward that I didn't need to bother with the bag trick, because I had done a right proper selection of the right drugs and levels to insure my death... Which did happen, I was just fortunately enough to have an Emergency Room full of with doctors who understand necromancy and can bring life back into a fresh corpse. - See I empthize with your desire to die, been there done that - more than once, but was only successful at it once. Live and learn, or as the case may be attempt to die and learn.... yeah there were a couple other attempts I don't talk about, I'm such an utter failure in life, i can't even kill myself properly... I Just hope from my educational here you won't have to go through that horrible experience.
The alternative method, which is the method I'm saving for the next time I do my own self murder, is to get at least three times the recommended dosage of heroin.
Typical starting dose for people who never used Heroin before is between 10-20 mg (injected), so you want to have at least 60 mg to be certain. Personally I would round it up to 100mg.
You will also have to learn how to cook it (prep it in a spoon so you can get it into the hypodermic). Look there are sites for that
http://www.drugs-forum.com/forum/showthread.php?t=41977 (will the wonders of the internet age ever end?)
Then there is the whole injecting thing you need to learn. Oh look, Youtube has videos on injecting:
Understand you need to have a little practice hitting a vein. I strongly suggest a week before you do off yourself that you get familiar with what it feels like to hit a vein. I normally suggest injecting with distilled water to people who want to start slamming drug, to reduce chances of infection... but hell your going to kill yourself anyway, so use tap water.
With injection, you have seconds - mere seconds before the impact of the drug you are using hits. Longer if you tap into a foot vein. The reality is, which few people seem to know, is that it takes a bit longer for a drug to reach its full effect when injected in the right arm, than in the left. My goodness, the amount of meth I wasted by shooting up in the right arm, never got the full impact of the rush as what I get from the left arm...
I digress, you have less than half a minute once you inject to do anything. That is barely enough time to pull the needle out of your arm and throw it down... Yeah there is a reason why so many heroin OD's dye with their needle in their arm... Its that quick.
Draw back, the person who finds you will most likely think this is a
drug habit gone dreadfully wrong.
Again, purge the system prior, empty the bowels and bladder, refrain from food for 48 hours, fluids for 12... We don't want to leave a huge mess for your finder to stumble upon.
Have you thought about your note? It is traditional to leave a nice note either blaming everyone or trying to assure everyone that it wasn't their fault that you offed yourself.
And what about your insurance? Will it still be in effect if you kill yourself - many policies just flat refuse to pay in cases of self murder. So if that is the case, what happens to your body?
If you do not have insurance and don't want the family stuck with the costs of burial or cremation, might I suggest a living will insisting on donating your body to medical science? I would check around my local area for medical schools, and ask them what their policies are on accepting fresh corpses for the purposes of medical experimentation and of course education. Many will not only utilize the body in many fascinating ways, but will dispose of the remains at no cost to the family.
Lastly, your finder.... usually we don't get much say who finds us when we do it... However in the case of the Heroin OD, you could actually place a 9-11 emergency call just before you hit the vein. Even with the usual 10 minute response, I fear with that much heroin in your blood stream there isn't much they really can do except haul off the body.
This will save any unfortunately from discovering the body....
When I did it, I had a friend with a key and they were all down with the idea of walking in and finding my dead body on the bed. She was kinda cool with death, and the whole goth scene... Rare Gem - she also had a medical background so the idea of finding a body was not going to upset her lunch or breakfast or anything like that. Got someone who you can give a key to your place that you know won't get all freaked out and go totally insane with guilt or something?
Yes, as a matter of fact I have thought about suicide - a lot - perhaps a lot more than you have, if you have only gotten to the 'how do I do it' part and haven't considered post murder clean up, you have definitely not thought enough about this subject.