Hello.
Unfortunately, there is no way for anyone over an internet message board to know what that could be. You need to see a doctor asap for evaluation and treatment. I will share that I had my gallbladder removed in 2000 and was having symptoms similar to yours. I've also had similar pain and it turned out to be a herniated disc in my spine at T12/L1.
If cost is an issue, look into free or low-cost clinics in your area. If it becomes an emergency then get to a local hospital emergency room right away. They must treat you regardless of ability to pay.
I hope you can get this resolved soon.
Click on my user name or avatar picture to read my story.
Blessings,
Dave