What could this be?

For the past month or so now, I've felt a little off. I feel nauseous immediately after eating and the feeling lingers for a few hours afterward. I've also been feeling exhausted constantly as well as having a lot of pain all over my lower abdomen, chest, shoulders, and back. I've been experiencing more headaches recently, as well as migraines. I've been having a lot of cramping too, to the point where I'm unable to stay on my feet. Nothing I do helps any of these symptoms, they just pass on their own eventually. Also, my period has been starting up to almost two weeks early and is mostly spotting for the past three months now. I have been trying to lose weight too, though I seem to have plateaued. I am also TTC.