Maybe try working on your PNC first? A lot of the thoughts and beliefs you have that underlie that are probably driving the anal sex fear.

If I had to guess it's probably something along the lines that anal truly makes you GAYYYYYYY (caps plus wailing sirens for comedic effect) in the eyes of others, or that a submission boundary has been crossed. That's why working with shame emotions is so helpful - most people can spend a lifetime trying to avoid, numb out from, distract from, or medicate away those feelings.

Force yourself to actually welcome in and experience the feelings of shame and submission and let them tell you what they mean. If you've never done it before, look up mindfulness exercises and then apply that to feelings of shame. Just a little trick I've learnt from many years of therapy ☺️