Let me offer something I always offer to people in your situation, with th preamble that I hope you won't get offended and give the notion a serious consideration.

There is a certain degree of inflated self-importance that very often accompanies social anxiety and the thoughts you are describing. This might seem paradoxical - you are isolating, you cannot face other people, so you are in a weak position, and yet I say that you are full of self-importance?? But bear with me.

Most other people, as has also been said above, are preoccupied with their affairs, too preoccupied to care one way or another about you. You attribute to them negative thoughts about you, but still, thoughts about you. That is where inflated self-importance comes in handy as a concept - you create a world in your mind in which other people are focused on you, except in a very bad way. You are the center of their attention, but in a negatively tinged fashion. And I suggest that you consider that you are not the center of their attention in any way, including negative.