As others have said, it sounds like you are just being paranoid. Most people won't really make the effort to talk to people they don't know. It's easy to think it is you as a person but really it is just thats how a lot of people are. Why don't you go up to people and start a conversation with them? Is it because you don't know how to start the conversation? Because most likely, that is the reason they don't do the same to you. It isn't because something is wrong with you, people just don't like to come out of their circle.
As for your friend, just talk to her or text her. Just say "Hey, how are you?" This will show her you guys are okay. She probably feels as awkward talking to you as you do talking to her right now. You both are waiting for the other person to talk first to see that everything is okay. If shes really your friend, she will understand fights happen and will be fine going back to they way things were. If she tries to avoid you just because of some little argument, then she isn't the kind of person you need in your life.