Sexuality question

hi so no offense to anyone part of lgbtqia+ but this is just what I have been dealing with personally. So I have always liked guys, I have only slept with them and I liked it. But lately I’ve been having intrusive thoughts about me being bi. it gives me anxiety by the thought of it, so i know I need therapy for that. but how do I stop my thoughts from getting to me? Like I can’t see myself dating another woman nor doing anything sexual with them. Somedays however I can see myself kissing them but that’s about it and other days I can’t see myself kissing them at all. What does that mean? Also since I have been experiencing intrusive thoughts, my mind likes to tell me that I may have a crush on my best friend which is a girl and I don’t want to have these thoughts. I have never liked her like that before so idk why now. Please help, I’m just confused. how do you know if you’re actually bi?