Am I normal?

I think I have a problem when it comes to a relationship. When I start talking to someone everything is cool but as soon as the person start to like me or I like them, millions of things comes to my mind.
For example: I feel so uncomfortable in public, I think everyone is watching us etc. I also think why would that person like me it’s impossible. And I eventually messed things up because I don’t speak about my feelings and I realized this year that every guy I once talked to had at some point asked me “What’s wrong? It’s like you’re not attracted to me or something’’.
I dislike saying yes to a date because I think that in this time as soon as you say yes the guy automatically thinks he’s getting a kiss or more at the end of it. I rather be friends with someone and eventually develop feelings the other way doesn’t seem to work for me.
I’m 20 years old and never had a relationship, maybe it’s my fault I started thinking.