I'm so sorry that you are worrying and suffering. Even though you're scared and nervous right now, it's better to finally find out exactly what's causing this and get the treatment on board. In this day and age, almost everything is fixable.
My husband has severe back pain and is on Lortabs and Amitriptiline? to help him sleep due to pain also. I hope you are able to get some sound rest.
I will be thinking about you and praying for you. Terri