I get it. You care about what everyone thinks and you're constantly trying to live according to the things your friends have said to you or about you. You're a perfectionist, so there's always room for self-improvement. You also care a lot about other people's feelings, so no one's opinion is invalid. Guess what, some opinions aren't worth thinking about.
People are rude and selfish and usually, they're only thinking about themselves. People can also be kind and sympathetic, but if you're stressing over what that person might think or say about you, stop. Trust me, they only said that because they were thinking about themselves. If you're as hard on yourself as I think you are, you probably beat yourself up over any criticism you receive. Even if it's true, you have to take everything with a grain of salt.
You don't know that person's motives. What if they're just jealous or insecure? What if you just happened to be there when they were looking for a whipping-boy? I understand that you don't want to be hated or talked about, but it's going to happen no matter what you do. If Jesus couldn't make everyone love him, you can't either. It's actually impossible.
Speaking of impossible, some people just weren't meant to be friends, and you shouldn't feel guilty for that. Be with people who say positive things. It's a sign of immaturity and insecurity when your "friends" are always trying to put others down. The only reason anyone would do that is that they want to feel superior. Be with people who don't have to put others down just to lift themselves up.
Girls want the approval of guys. That's just a fact, and it's completely natural. But you can't earn the approval of every guy. Sometimes they're just not going to like or encourage you, no matter what. It doesn't matter how much you suck up to them or try to coddle their fragile egos. And they are fragile, but they hide it.
Remember to always consider the source. People's opinions change every five minutes. You can never know for sure what someone's thinking about you, so stop trying to shape yourself into the person you think they might want to be with.
Even if you feel like you can never let go of this insecurity, fake it till you make it! Act confident and talk to yourself the way you would talk to one of your friends. If they were constantly worrying about what everyone thought of them, you would tell them to stop and list all of their positive traits. Do the same for yourself.
Here's the big shocker: no one's actually thinking about you. Maybe they act annoyed when you're around, or they roll their eyes. Accept it, address it, and move on. If it bugs you that much, ask them why they're acting that way, do what you can to remedy it, and then move on. In the real world, you'll be forced to stand up for yourself, so you might as well start now.
Remember, some of the biggest success stories started out as "disappointments." J.K. Rowling was almost homeless at one point. Steve Jobs was fired from the same company that he started. Bill Gates co-owned a failing business and became a college dropout.
It doesn't matter that you feel like a failure or a disappointment. Feelings don't equal truth. You don't have to be afraid anymore, because chances are you're worrying about nothing. Most people don't even think about the way you do. Of course, no one wants to feel like a failure, but you're exceptionally sensitive to what other people need. Your greatest strengths are also your greatest weaknesses, so use that sensitivity to help others without hurting yourself. Just remember you're your own worst critic. Being yelled at or hated really isn't that bad when you consider the source, and honestly, that's only the worst case scenario.
Best case scenario, you let someone down, they realized that you're only human, and you both moved on. Let it go, babe. Life is good, and we call those people haters for a reason.