Please! Please! Don't hide from them and eat alone, that seems to be the easy way, but by doing that you are isolating yourself, and that ( please believe me) is not the thing you want to do! When we have Chronic Pain we all tend to want to do that, and the more we isolate ourselves the more alone an isolated we become. Then all of a sudden one day you will find yourself really alone. It all starts off so innocent and benign, and the next thing you know, ......well you really don't want to be there. You know I really don't know if you need to become a stronger person, I have seen your post, and you do seem to have allot of inner strength! At least I think so anyway! Maybe you need to look at yourself and even get help if you think you need it, and try to find what it is about these people and their questions and comments that really bothers you so much! and why!, and then try to address and problem solve that. I don't know maybe you already have? Anyway it is just a thought! Anyway I just don't think you should do the isolation and avoidance thing, I have done that, and it was a terrible mistake!
I do hope you get it all figured out and resolved!