Why? Others shouldn't affect you that much. There are very few people in your life whose opinions you should actually care about. It isn't just you, everyone has this. Figure out who those people are and put energy into those relationships (which isn't always easy). That's where you'll get your biggest wins. Beyond that, be mindful of how you treat others. Be good to people and you'll increase the likelihood they will be good to you. If you are doing those things and people are still fucking with you, it is most likely they are simply assholes which isn't something you have control over. Let it go and enjoy life.