My commitment issues are ruining my dating life

I am writing on this forum out of desperate need. My commitment issues are becoming a real problem for me. At first I thought it was just me liking the thrill of the chase because whenever I like a guy, I start losing feelings when I find out he feels the same way. Behold it is happening again with the guy I’ve been crushing on for a while now who just told me he has feelings for me. I know I like this guy but I can’t seem to stop doubting my feelings. This isn’t the first time something like this has happened and I’m getting sick and tired of it. I subconsciously ruin every good thing and go after guys who show me no attention, putting myself into miserable situations. At first I thought maybe it’s because I’m just not looking for a relationship but I’ve been like my whole life and I have to be ready for one sooner or later. And I’ve been thinking about wanting one for a while now. But now that maybe there’s a chance (not getting ahead of myself), I feel like the idea of a relationship is just not for me. Is there anybody who has gone through this and overcomed it? Please! Any advice is appreciated.