I was like that. Sleepless nights replaying coversations ive had with people thinking what i should have said. Its debilitating because i would spend hours rehearsing conversations and interactions trying to keep good appearances, id make bad financial decisions based on what others would think. The list really goes on.

I dont know you so ill just say what it was in my case.
I thought too little of myself and too much of others. I thought this manner of thinking made me a good person. To some extent i still do.

I realised that people suck. Even the ones you hold in high regard are flawed in some way. People are too concerned with themselves to care about you. People are only selfless when others are watching. There are more crappy people out there than fish in the sea and If they like you because you conform to their will its not someone you should want to be associated with. i realised i should be more selfish.

Started spending my time doing things i like instead of rehearsals. allowed myself to be myself.
I started taking pride when i get stared down by someone because it means i dont conform to him or her. I see who they are and what i dont like about them instead of thinking who i should be to please them.

I should say that ive become very apathetic and would recommend not caring at all but find a nice ballance in between.