I've been having excruciating abdominal pain for about 2 months now. I've been nauseous and vomitting, pain in my back, bloated, eating a lot, and headach?

I am sorry to hear. This , why you have to suffer all this time, please go and see a doctor and have him check it out.
Seek medical exam. Possibilities include problems to your appendix, problems to your gallbladder, problems to your intestine, problems with your liver, problems with your stomach. A thorough physical examination of your abdomen can give more information.
What doc say? I hope you are not serious about two months of excruciating abdominal pain without seeing a physician. So, i'll just take this a test question. 2 months abd pain, n&v, bloating, pain in back, ha and excessive eating. I'd think: parasitic infection, like tapeworm; gall bladder disease high on list, pancreatitis, or something blocking panc duct. Ok, how it's time to c what is going on.