I always regret having sex.

I hate being gay. I've had lots of bad experiences socially and sexually, and continue to be annoyed that people do not practice safe-sex and like to be too promiscuous. I have given up on it. But my T keeps encouraging me to be sexually active. Sex has never really been my thing though. I almost always regret having it probably because I was raised to be asexual and being asexual is still the goal and comfort zone of my inner self. I don't fit in well with the LGBT community either. I keep telling her that I have given up being gay / sexual but she is persistent. I really want the T to work on my other issues - c-PTSD and career problems and have told her that. She is preparing a list of goals and wants my help in setting them. This is going to lead to a disagreement because I do not want sexual goals on the list. I have told her that I'm asexual and she says she accepts that but that she believes that sexuality is fluid. In other words, my sexuality can be changed. From all my readings, that's news to me. If I am asexual and if asexuality is my goal then why should that be changed?

I don't agree with your T at all. Sexuality can be fluid sometimes, for some people.
Sorry unguy, that's gotta be so frustrating. Don't let her pressure and persistence force you to do anything you're not ready for or interested in.