It's not personal

While you are fretting about other people's perception of you, they are not thinking about you in the same way. Sure, it is possible that you may pop into their head, but not to the extent that you may think. For you to be in someone else's thoughts you have to matter to that person. If you don't matter to that person, they have to be reminded that you exist. 

For example, when you ended a relationship with someone you mourned them leaving your life. After a certain amount of time the person leaves your immediate thoughts as if they were never there in the first place. They may pop into your head from time to time, but that is about it. They have become unimportant. 

This is how you are to the majority of people you know. Even somewhat to those that are closest to you and you to them. For that reason, you shouldn't take anything personally. Carry on with your life like it really doesn't matter what others think. Because it doesn't. <3