Is there anything I can get from the grocery store or drug store for my biliary tract disease stomach ache until I can see a doctor?

Perhaps. If there is no evidence of infection (no fever, chills, sweats and you're improving), you can try a clear liquid diet and then slowly advance to a low fat solid diet. Simple analgesics like Aleve (naproxen) or advil can help. But biliary tract infection can be lethal. You're playing with fire if you're not under close supervision. If recurrent or complicated, surgery is indicated - safer early than late.