I don't find that ice works too well for me, heat is better.
And yes, the pain is awful, and unrelenting.
I suspect that this is sciatica or pressure on the nerves caused by my prolapsed disc (did that many moons ago).
Whereas the treatment used to be loads of painkillers, valium and rest, it is now accepted that you should exercise as much as possible.
Am taking Co-dydramol (basically strong paracetomol) at present, not allowed anti-inflammatory cos of heart medication.