Why am I like this

So I have a really weird problem personally idk even how to say this. Every time I like a guy and he likes me back I immediately stop having a crush on him. Guys that I like who do not like me back I continue to simp over but once they show any interest in me I don’t like them anymore and I don’t know why. Also relationship repulse me. I don’t want to be in one I kinda wanna puke when I think about being in a relationship or when I guy wants to date me.