Sympathy, mine's letting me know this morning.
I use paramol (or Boots own equivalent) which is a combination of paracetamol and dihydrocodeine - the latter is a highly addictive painkiller when taken 'neat' and also constipates you something wicked. However in the paramol form it's only a small amount. It takes the edge off nicely, can make me a little sleepy if I'm sleepy anyway, but does not have anything like the incapacitating effects of the full-on prescription painkillers.
You also need something to take down the inflammation around the nerve channel. I have Voltarol tablets that I take as seldom as possible (prescription). They are truly vile but will bring down the inflammation and give you a break from the pain. Voltarol and Ibuprofen gel are available without prescription - I'm less convinced of their effectiveness but might be worth a try. Also use ice-packs - some frozen peas in a sandwich bag, wrapped in a teatowel so you don't give yourself frostbite and applied to the pain. You can keep re-freezing and using as needed, only don't then go and serve them for dinner by accident as Mr O'lady did.
These strategies do not cure the condition, although they give you a calm time with less pain so you tense up less and healing can start, but as campellking says you need some form of physio to deal with rehabilitating the shoulder and not harmng it again.