Crying after sex is not as uncommon as you might think. The rush of hormones and release is a lot. And can affect us all in different ways. Some people vomit. Some feel sleepy. Some cry. Try masturbating, understand what feels good to your body. Where is there a release or enjoyment. Can you feel your body respond emotionally. If this if perhaps more psychological than hormones - seek some advice from a registered sex therapist. You mentioned trauma from past relationships which would suggest there is something held subconsciously for you here. That has not been resolved. Speak with someone - talking therapy can help us overcome and find pleasure in those new relationships.
I feel you'd benefit from the freedom programme (women's aid) or some therapy x