The beginning of your story was like someone was writing about me. I am also 26 and my husband is addicted to Oxycontin. He started the same way taking it for back pain caused by his work in construction. He hid it for over a year and lied every chance he got. He did finally come to me and confess and asked for me to work with him to get help. We have tried so many things (including suboxone, inpatient detox, therepy) and I thought we were doing so well, but in my Valentine's day card he informed me that he has been lying to me and he has started taking them again.
I can't even imagine your situation with his family being the ones supporting his addiction. I really feel for you. The one thing I will recomend is making sure that you have plenty of support for yourself too. It really takes a lot out of you and it can be very depressing if things don't go as planned. Just make sure you take care of yourself. I wish you lots of luck and strength.