Hey blondone and welcome to BL.
It seems like your having a stress or fear reaction due to the traumatic events of your past, which im very sorry you had to experience. As others have suggested MDMA therapy has shown great promise for treating symptoms like this, but I would also agree with herby that it needs to be accompanied by a therapist who is experienced and can skillfully direct positive ends. I would look into this, but its still very new line of therapy and may be difficult to find.
Have you tried a traditional therapist? If not I would explore this avenue. If you do I would certainly do my research and find a good one as they are not all created equal.
I would consider looking for a therapist that specializes in helping people heal from traumatic childhood sexual abuse.
I think you will have to find away associate at a very deep and profound level that sex can be a wonderful and loving act as opposed to the very negative acts that were forced on you. Those were not and need not be associated with sex. That experience was not sex so its not associated with sex with your partner, even though your mind is correlating them. Have you been able to forgive the person or people that did that to you. Forgiveness is not for them, its for us and lets us free from the grip of awful things and the people who did them to us. What happened to you bears no reflection on you. The only person its a reflection on is the person who did it and you carry no aspect of it. Please consider forgiving the person or people who did this in order to try and heal yourself and cast off any power they still hold over you. A good way to try and accomplish this may be seeing a therapist and I agree you may want to look into MDMA therapy as it holds great promise for this.
I hope you can find the relief you're looking for and deserve.