I’m afraid of sex

I’m 22 and have had sex with 5 partners since I was 18. I have been with my current bf for over 3 years. For the first 1.5 years we had sex frequently (average of 5x a week). I then contracted mono and suffered from recurring UTIs. I came to associate sex with fatigue and pain, during and after. I’m now mono free and have been on low dose antibiotics for 6 months that have kept the utis away, but I seem to have developed anxiety around sex. We do it once every two weeks or so, and any time it seems like it’s going to happen I feel tired and scared. My boyfriend is feeling neglected, but he is respectful and doesn’t pressure me. Has anything like this happened to you? Is this normal or do I need help? Thanks