You’re mixing two TOTALLY separate things here.
He was nervous and didn’t finish. That’s totally legit and happens to a lot of men, and it’s honestly a good sign that he really likes you. He was putting pressure on himself to perform because he likes you.
You have past trauma. You don’t seem like you’re trying to use him as a therapist or dump your problems on him. Do the hard work of dealing with things with a professional. Of course your partner can/should support you, but only to a certain extent.
Having baggage/trauma does NOT make you undateable. Having baggage/trauma that is completely unresolved and that you aren’t working hard to heal from certainly can though. Solution: get to work with a professional, keep your boyfriend, everyone wins!
Pro tip: if you want him to not have any boner issues next time, you should be really understanding and tell him it wasn’t a big deal and that you understand.
Now is not the time to dump all your baggage on him.