Getting On My Nerves

I'm suffering much from a 'trapped nerve' in my left shoulder. I have had sessions of physio  and taken pain killers, used hot wheat bags etc. etc., but the condition persists. More or less any physical task triggers it and it takes a very long time for the pain to go and the muscles to relax. Heat does help as do certain exercises, but very slowly and sometimes the pain is quite acute. The practical result is that less and less gardening is being done, and almost no housework. Obviously I hope the situation will change.