Are some people just naturally tighter/looser than others down there?

[Teox]

There's no such thing as a "tight prostate" your physician was misinforming you. The prostate gland is 5" inside your rectum, not anywhere near the sphinter.

What would you suggest I do?

To answer your question directly: NO!

The sphinter is a strong muscle - and can be "flexed".....so, the reality is, you're apprehensive about anal sex being painful and so you're "clinching" your sphinter muscle which makes it almost impossible to get even a pinky in your rectum.

Once you find a guy or situation where you feel 100% safe and with a partner who's very patient, you'll be able to enjoy anal fun. But, until you learn to fully relax, and a guy will take the time (and lots of lube) and you TRUELY want to bottom, it will be tough and even painful.

I have relaxed and felt safe and trusted my partner, I've taken time with plenty of lube, I TRUELY want to bottom but I don't like pain so maybe that's my problem, The pain. Maybe cause anal sex is truely unnatural?

Not really. Look upon it as going to the gym, first time will feel like shit, but after a while the pain will subdue and you wouldn't notice any. Of course you don't have to be a bottom that's your choice, but if you really want it, just know that the more you exercise doing it, the better it will feel

Scientist need to create something to make it easier.