What causes upper abdominal pain that shifts and worsens in the back area?

Hello doctor,

I have been having pain in my upper abdomen area, that also shifts to my upper back area, and the pain is so much worse. I have tried an antacid, but it does not provide relief, and it has been three days now. What should I do? Also, I have been working these days. I think that affected me too, because I was doing a work-from-home job and got tired quickly while traveling. So please tell me, is it because my nature of work changed, or is there some other issue? I have searched on the web, and the results are so scary and depressing. Please help. It has been three days, and even the home remedies have not been effective. It gets even worse when I stand up for a long time or while sleeping and also when I am full after eating. I get tired also so easily. As I said earlier, I have been in work from home job, and my body is not very energetic for traveling to an office. And while traveling, I feel so low and kind of sleepy. This has happened to me several times, but it was only for a few hours. This time, it is so much worse than before. I have also changed my diet this month. I have been eating only fruit salad in the morning and normal food with less oil. Recently, I ate oily food after a long time. Please help.