How do I get over imposter syndrome?

I now identify as a lesbian and know for a fact that I am not sexually or romantically attracted to men. However I keep struggling with internalized homophobia and imposter syndrome, as I used to have feelings for boys that I thought of as crushes when i was younger/confused. I felt pressured to have a crush on a boy even though I knew that I would never want to confess to them and that the thought of dating a guy felt wrong and uneasy for me. Due to my every friendship with a guy being read as "oh so are you dating him?" or "oh so you like this male character, it has to be a crush!" by friends and family i internalized that and for the longest time was convinced that every positive emotion i had for a guy was a crush, and even went as far as to step back in identifying as lesbian and called myself bi for a few months just so that I would not disappoint this guy i had befriended if he developed feelings for me (and also because i was so desperate for any positive attention that i was willing to do whatever for validation that i am lovable) , because i was so afraid that if i said im not interested in him romantically i would lose a friend and being deadly scared of rejection i thought that i could tolerate a relationship with him if it came to it, later i did realize that i would never want to be in a romantic relationship with the guy and the thought of that scenario filled me with dread to the point that i just stopped talking to him to make sure he would not get anything wrong from me so that i would not have to reject him. As a kid i picked out a boy in my class that seemed the least threatening and most like a romantic interest from a book i had read and just thought, oh he is kinda nice-looking this must be a crush. I never pursued any of them (and didnt even want to!) and just replicated what i thought i should be feeling and that way gaslighted myself into believing it was a real crush, but every time i thought about actually dating any of them instead of just having this passive "crush" i instantly lost any feelings and just went oh fuck no, also i never thought about them in free time or fantasized about a relationship or anything. So these were all pretty clear-cut examples of comphet, but i still feel like a "worse" or a fake lesbian because i didnt know from age 5 and thought i was bi for pretty long and because i didnt have obvious celebrity crushes on girls as a kid. This is stupid and internalized homophobia and insecurity speaking but damn its hard and sucks.