Anyone else seem to give up on friendships eventually?

I don’t know who my real friends are or were. I’ve never known or can’t tell who is a true friend or not to me. Is there something wrong with me? I always just feel like every ‘friend’ I make and meet are just fake? Like I’ll think I had a good time with them, they’re there for me at times, they don’t make me feel alone, I have someone to talk to and share stuff with, go to places with. But then they’re not always there for me or I feel let down at some point. I know no one is perfect but I just don’t know.