Sounds just like me so many years ago. May I make a suggestion? (if not, just totally ignore) Start with what you CAN change. Maybe that can be figuring out, with the help of a doctor, the cause of your pain? Or getting some meds for it? Or maybe, stock up on some healthier foods that you can binge on? Healthy stuff that you like, like fruit? I know the whole point is to not binge but, it'll take time to get there.

As for your mother, how about if you told her, "Complain, but I'm going to tell you the truth at the end. If you don't want to hear that then stop right now."

Just ideas. Maybe it'd be cheaper moving to another city or, change jobs? In any case good luck.