How to get rid of thoughts that disturb you?

I have few people who love to give comments, mostly negative ones, so that the person gets discouraged or feels bad. Because of this, I have kind of developed an unhealthy competition that I must do better than them. I never want to develop this thought because I want to grow as a person but because it has been in thoughts, I feel like finding where they are since they keep intruding me in whatever I do. Please help me on how I can change my approach and not get affected by what they do or not. How can I release these thoughts from my body and mind?