Hey dude, I'm sorry to hear it's so rough. A doctor is out of the question? Do you have any chronic illnesses or disabilities? There has to be help out there. How are you doing eating wise? Getting enough nutrition?
There are numerous causes of right-sided abdominal pain, including but not limited to liver infection/inflammation (hepatitis), gallstones (cholelithiasis) or gallbladder infection/inflammation (cholecystitis), kidney stones (nephrolithiasis) or kidney infection/inflammation (pyelonephritis), bowel infection/inflammation (enteritis, colitis, or appendicitis), hernias, or cancer. Given your poor eating habits, you may have gas and/or indigestion. This symptom checker from familydoctor.org can help narrow down the possibilities: https://familydoctor.org/symptom/abdominal-pain-stomach-pain-long-term/. However, you should still see a doctor who can take a detailed clinical history, perform a physical exam, and order any necessary lab and/or imaging tests. Furthermore, you should see a psychiatrist for your agoraphobia and other mental issues. If you have no money, apply for Medicaid or seek out free clinics in your area.
I really agree with Medicaid. This could be really helpful to you. Even a meal delivery service could be included in your services. But you have to get on their radar. How do you pay your rent and such?