Why can't I be myself?

I always look to see what other people are doing before I make my own choices. I'm tired of doing that but it's a habit of mine. My psychologist says that I'm a perfectionist. I do kinda go outta my way to be nice and do things for people for no reason. I feel like I need to look out for my best interests but I feel like I'm being selfish when I think like that. Can somebody help me out pleasee?