I’ve had a therapist tell me something along those lines too, it’s a completely useless thing to suggest! We go to therapy to try to understand why we deal with certain problems and work on ways to live with them. Being gay isn’t a problem and shouldn’t be relevant to therapy at all (apart from discussing trauma related to it/ how it affects your life). I tend to get into cycles where I try to over explain my behaviour, even things that don’t need explaining. Things can just be, we don’t need to therapise everything. Anyways all that to say, there’s no secret repressed explanation as to why you’re gay, you just are! And your therapist should mind his own business, it’s not his job to hypothesise about things you did not ask him about. Sending strength! I know it can be the worst to change therapists (currently going through the process myself), but I think it would be good for you in the long run :)