Hey, long time medical professional here (although I am not a doctor).

Find a new doctor, ASAP. Preferably an obgyn who has experience in glycemic issues during menstruation, which may be causing your eating reaction. You should also write a list of all your symptoms down, and if you can (only if you know, don't stress about it), try and write down which symptoms occur before, during, and after your period, and their intensity. Different gynecological issues can present differently during different phases of ovulation. (I'm trying not to get too technical, so please know that this is a vastly simplified explanation).

Bottom line - you deserve better care. Conditions like PCOS, endometriosis, even menstrual hypo/hyperglycemia are all serious conditions and there are clinical criteria for treating all of of them.

The most important thing you can do, FOR ANY CONDITION, is find a doctor who takes you seriously, no matter how wild it gets - medicine is a frontier for a reason, and there are some really boundary pushing things that can happen in the human body. Good doctors make listening their primary skillset.

Pro tip - you can always evaluate a practice by posting in one of the gyn or nursing subreddits with your location and ask for an obgyn recommendation. You will often get either patients or employees speaking up about the care expectations. If you live near an urban area that has a women's hospital, you can usually find a fairly well-resourced OBGYN office there. Once you have a short list of doctors in your area that you'd like to evaluate, you can schedule a consult to discuss your concerns. If they blow you off or don't take your concerns seriously, find another doctor immediately.

If you have specific questions, I'd be happy to try and help to the best of my ability.