Welcome to the chronic pain forum. Since you're a regular member, you know we're not docs and can't give you medical advice, just support and share experience. People react very differently to medications, so even sharing experience isn't any indication that's how you'll respond.
My first question to you would be are you decreasing all these meds. under medical supervision? If not, then you really should be. Also, chronic pain generally means that you don't get rid of all the pain, just get it to a manageable level. And along with that there are always trade-offs with medication side effects. I can't tell you how long the psychological symptoms will last for you, but if your pain isn't managed effectively, then you're likely to be depressed and even with the cymbalta and wellbutrin they may not be enough on their own.
I think you need to talk with your PM doc and share your concerns about the side effects of the meds, and see if there are other options for you. One thing I'd caution that if you're decreasing or eliminating your meds without your doctor (I'm not saying you are, I just don't know as you didn't state either way) he/she could be justifiably unhappy with that, and you may not even want to continue to see you as a patient - most especially involving controlled substances like oxycontin.
If the only problem is that you don't like being dependent on the medications, but they were working for you and you were motivated to do things, etc., then it may be making peace with the issue most of us have to make peace with - we need these medications to get the best quality of life possible.
Another helpful thing is to find a good pain management therapist (psychologist, clinical social worker, etc.) to work with, to help you assess all this, as well as teach as many non-pharmaceutical methods as may be helpful for you.
Hope this helps a bit.