Not Sure Why I Don't Enjoy Sex

Hello All,I am looking to find out if anyone has any resources/insights that I could use for some self evaluation of why I don't enjoy sex?So here is the back-story... I was closeted for a long time (mid 30s now) and just recently came out. I have always dreamed about what it would be like to be with another guy. So in recent months I have been trying to see what I am missing. I have been with a few people now (4), and I really enjoy making out (hugging/kissing/petting), but as soon as it gets serious I lose my libido. Once the clothes come off and it comes time for actual sex I get soft. I will give a BJ or my ass for the guy to get off, but I am not into it sexually. At first I thought it was performance anxiety, but it would seem like that should go away sometime right? The longer it goes on the more I think that maybe I am a/demi-sexual? Maybe I spent too many years in my fantasies? It is frustrating because I really love the idea of a man to hold all night, someone to share my life with, but sex is a huge ingredient to successful relationships and what if I cannot perform in that area? So maybe I am just destined to be alone. Wow that sounded dark and whiny.So I am looking to find out if anyone else has ever been through something similar, or if anyone knows of any resources I can research to better understand what is up with me.Thanks in advance.