Don't know if someone likes me

Sometimes I have these phases when I don't know if someone likes me. I feel like I get too obsessive with people who I want to be friends with. I'm not as bad anymore, but now I get paranoid. If one little thing feels off, I assume it to be the worst. If a friend doesn't reply to my text or wave at me in the hall, I think she's mad or thinks I'm annoying or hates me secretly.