He is guilt tripping you, no doubt.

As other posters have said - you should never, ever be pressured into doing something you are uncomfortable with even if it is not sexual. Anal sex is a hard limit for a great many people so please don’t allow him to shame you for speaking up and voicing your concerns. A good partner listens. I do agree with one thing he said though - you may not be fully sexually compatible.

However, lots of people have kinks that their partners don’t enjoy and anyone who has ever been in a long-term relationship or marriage will tell you - you have to compromise. Sometimes that means you can’t do stuff you want, that doesn’t mean you will be unhappy, you just find stuff you want to do together. This behaviour from your bf would be a major red flag for me. Personally, I think it takes a long time in most relationships for both partners to fully let go and let their guards down emotionally and sexually. If he is like this already, can you imagine what your relationship would look like further down the line?

Good luck with whatever you do, you are definitely NTA.