Is OTHER wrong in the post ? POST : Obviously a throwaway account. Also sorry if I make any mistakes, English isn’t my first language.

Me [M24] and my boyfriend [M26] got together about 5 months ago (we‘ve known each other for maybe 9 months before that). I‘m very happy with him and he‘s pretty much everything I‘m looking for in a guy. There‘s just one big problem in our relationship...

Having anal sex with my bf is unbearable for me because he has a really big and thick penis. It’s not exactly the length that’s the problem but rather the girth. I am by no means inexperienced when it comes to anal sex, but trying to receive him just hurts like hell. We‘ve tried everything we could think of (different positions, different types of massages and relaxation techniques before sex, etc.) but I always end up being in an awful lot of pain anyway.
I tried enduring it two times, thinking I‘d eventually get used to it, but it’s just not working out the way it should. He obviously doesn’t enjoy having sex with someone whose face clearly says „I hate this“ either.

Needless to say, this is a very frustrating issue. We both like having sex, but if it doesn’t work it just doesn’t work, you know? We still pleasure each other orally and with our hands, but at the end of the day that isn’t really enough for either of us.
Switching positions entirely is no option either since he doesn’t enjoy bottoming at all.
I feel a little guilty and embarrassed about being unable to handle his size, especially after he constantly brought up the fact that his exes had no issue bottoming for him before.

He‘s made two suggestions on how we could fix the problem, but I rejected both of them:

1. Using poppers (I think using them often is dangerous and I don’t feel comfortable with the idea of drugging myself up just to have sex)
2. Having an open relationship (I get that I clearly can’t give him what he wants, but ofc I don’t want my bf to have sex with other guys while we’re together)
Since I rejected both ideas, he‘s become more and more frustrated with me and accuses me of not caring about the whole thing and evading the problem which isn’t true. I just feel like I shouldn’t have to give up my principles for the sake of sex, if that makes sense.
At this point I just have no idea what to do anymore. I know sex is a really important part of a relationship, but I just hate the idea of breaking up with him over this. Our relationship is pretty much perfect otherwise. He actually feels the same way I do (I‘ve made sure to ask him several times), but since we both can’t agree on / find a solution, I‘m scared of what might happen...

When I asked one of my friends for advice, he told me I should just get over myself and try out one of the methods he suggested, but like I said, I feel like I shouldn’t have to give up my principles for the sake of sex. When I explained that, he said I‘m being childish and that it‘s essentially my prudishness that keeps us from having a fulfilling sex life. Hearing that hurt and made my guilty feelings even stronger.

AITA for refusing to try out the things my BF suggested and maybe putting our relationship at an even bigger risk that way?