Everything can be seen as a learning experience. The question is are we ready to learn. If you chose to go back to your old job it might be a reason. Perhaps your psyche is telling you this could be an opportunity to learn some anxiety management. For me what would scare me is not having an out. What would I do if my anxiety was so bad that it affected everything else in my life? If you have a therapist, you might be able to make an action plan and perhaps include your boss. Realize that anxiety is currently an issue, but you have a couple of options when you need a break. Personally, the ultimate job that generates anxiety for me is a full time commission jobs. I tried a few, never made a dime! I commend you!