You're in the same boat as many of us.
I started years ago for a chronic pain problem with
morphine, but the drowsiness was too intense, so switched to oxycontin. It worked very well, until it was taken off the market in February. Now I've been scrambling for something to take it's place.
OxyNeo works well - I find it works just as well as OxyContin did - but gives me some stomach cramping (I'm very prone to this). Hydromorph contin didn't give the same relief that OxyContin did - I still had a lot of pain, even on equivalent doses. Also, didn't digest the tiny pellets inside the HMC capsule, and got a very raw ass from all the tiny pellets coming out.
So far, the thing that's worked best has been OxyIR. It's the quick release form of
Oxycodone - so same effects as OxyContin. You have to take it more often - my problem is that it should be lasting 4-6 hours, but I find I want to re-dose after 3-4 hours. Right now I'm taking OxyIR during the day, and OxyNeo at night (that way the stomach cramps don't bother me, because I'm sleeping, and I don't wake up in withdrawl from no oxycodone in my system).
Good luck finding something that works!