Ever have an eating disorder? You say you have anxiety, but are using weed for it. Weed can cause anxiety, so it can turn on you, though it does help some. I have no idea what's going on with you, but it could just be the anxiety manifesting itself in a different way because you haven't solved it in therapy but are just keeping yourself high as your solution. That might in fact be the best you can do, therapy is no guarantee of success, but if you haven't tried it you ought to at least give it a try. But if you go over to the anxiety forum, you'll see that many people got their first anxiety problems while stoned, as I did, as it tends to bring out of us things that haven't come out yet (or maybe never would, I don't know). Yet, weed does help many with PTSD, so obviously this differs by the person. I'm just throwing out possibilities here, not answers since it's an odd problem.
Have you had a doctor check it out for some possible underlying problem or could you be pregnant?
Wow this must be quite debilitating. The anxiety can not be easy to live with either. Have you considered seeing a homeopath, they will address the mental, emotional & physical issues. Best of luck. Hope you feel better soon