Counselor Wrote:D:
For Pete's sake, skip a day! It won't kill you!
(Pete is a double entendre)
Masturbation once a day isn't an addiction, to my mind. Nor even twice, it depends how horny you are, but it might also be telling of some sexual tenseness due to a disease, so if it could be that, you need it checked.
I see you're only eighteen and maybe you've not had sex with other people, just on your own, so the tenderness you're feeling could come from a number of things. Congestion has been suggested. You may, with too much force have ruptured something (in which case it needs to mend, which could be the urethra or some blood vessels (even small ones). Since the penis is very much innervated it'll feel very sensitive. Some rest might be a good idea.
Sometimes we pass stones through our urine (small crystals clusters formed in the kidneys which would become kidney stones (very uncomfortable, that) and that can chafe the lining of the urethra too (leading to some bleeding sometimes). Maybe check your intake of tea, coffee, chocolate and other things that can lead to kidney stones through uric acid (look it up online). Ask your doctor, anyway. Drinking plenty of water can help to pass the acid out and the stones too. Keep yourself hydrated.
If you have had sex with another person, it could be a sexually transmitted disease that needs to be seen to. You can get these from blow jobs as well as anal or vaginal sex, and even from someone with dirty hands handling your equipment so... (sorry for the grossness of this detail) especially if not using a condom (condoms generally keep these things from being transmitted)
That's all I can think of for the moment.