I'm scared of being unloved because of my outbursts.

What if my best friend starts to hate me? I can't take this anymore. People leaving me because I'm scary and unstable. I try so hard but every few months it happens.... I'm scared of being abandoned. My best friend said that I think too much. That if I stop overthinking I'll be fine. He said he's not going anywhere. He said "don't worry, I'm with you." So maybe I should chill and not think about things too much.