I think it's great that you're aware of one of the reasons behind your anxiety. That will help you work through it. I understand about the guilt--not fun. It doesn't ever let you relax!

Real friends will still be there for you even after a time when you were not as connected. I think it's part of growing as a person to sometimes be more separate from the people you love--that's how you find out who you are. Maybe this will help you to feel less lost over time. Then you will have more to offer them when you are close again.

It's painful to feel left out, though. It must be really hard to see them pay attention to each other while paying less attention to you. I would feel jealous. Hope things work out better in the new year!