Hello, and welcome. I have experienced the "organ cramping" thing myself (or something like it). It's scary as hell. However, I have discovered this: when I take a really good vitamin supplement, plus extra B-comples, and extra Vit D.... the cramping isn't as bad. So, I'm pretty sure it's some kind of vitamin/mineral deficit. Although, I did notice it was really, really bad just before they discovered my hypothyroidism, so that may play into it too. Also, wheat and dairy products seem to have an effect, so I've tried to stay away from them. Taking a course of really good probiotics was helpful too.
I would start with some good supplements (vitamins and probiotics) and a gluten free diet. Limit your dairy to yogurts. Limit your fats to about 30% of your intake, and no fried foods. Try that for about 10 days and see how you feel. You may need to experiment to see what works and what doesn't. You don't need Weight Watchers, most of us just need a new way of thinking and being, and that take some trial & error, introspection & feedback.
Ideally you would go to your doctor and share your concerns, perhaps get thyroid & vit D levels tested. In these times, with joblessness and lack of health insurance, I know a lot of people who just don't go see the doctor. Maybe that's your case too, I dunno. So do some experimenting to see what your needs are. Fitday is a good place to track things and share your journey. Good Luck!