Hello/? I Really Need Help In Finding Out What Is

hello/?
I really need help in finding out what is going on with my left arm and shoulder as it is very dibilitating for me as a result i am limited as to what i can do! I cannot flex my arm as it feels like someone is trying to rip it from my body as well as scratch my back wash my hair fix my glasses wipe dang tears from my eyes and so on please i just need to hear what you think it may be i have had x rays and am waiting on results i have had blood work also waiting and i am waiting on an MRI but am really in pain what can i do i am allergic to anti inflamatories as well as asprin and anything that even has a little asprin pls i need helpful advice