Stomach and back pain after eating

So I'm about a month into eating healthier and I've been having some problems. I find that shortly after I've finished eating, I start getting this terrible stomach ache. It literally feels as if I'm starving and it is so bad that my back hurts too. I'm honestly not sure what's going on and wasn't sure if anyone here has ever experienced anything like that. I have a history of heavy binge eating which I've controlled as much as possible over these past few weeks and am not sure if that ties in. My primary care is out of town and don't really want to go to a walk in just to be told it's nothing and I won't seem my psychologist again, who deals with my eating disorder, for another week. Any ideas? Oh, before it's mentioned, yes I know y'all aren't doctors or medical staff and that I can't use anything y'all say for self diagnosing or whatever. Just trying to get an idea before I actually do see a doctor. I can't remember not binging and when you binge your stomach always feels sick, so I'm actually lost here when it comes to dieting.