Heartburn

My heartburn is just so overwhelming. I can’t stop thinking about it. It takes over my sleep, I’ve tried everything there is to try but nothing works. I was prescribed Pepcid but it doesn’t work too well. I take it twice a day every 8 hours. I have some tums as well but it works for up to 2 hours. I sleep with my head elevated and sometimes I still experience heartburn. Now I think I might have gastritis. Under my left breast I feel a sharp pain, the area is swollen and when I put some pressure it hurts terribly! What else can I do to treat this heartburn!?