I'm taking 200mg Wellbutrin, 100mg Zoloft, 60mg Cymbalta & 50mg Nortryptiline. Also 1mg Xanax (alprazolam) x 3 and 10mg Oxycodone x6. Still depressed & anxious.

It depends. In my practice unrecognized Bipolar Disorder, Substance Use Disorders, and PTSD are toward the top of what might be contributing to your ongoing disability. If you have access to a psychiatrist with addiction medicine expertise, likely they can help. Finding competent help is problematic. Please continue to seek help. Not easy! There is help. A therapeutic relationship essential.
Quantity misleads. You are taking many medicines, but the dosage that you have given is in each case inadequate for a therapeutic response. In general it doesn't work to add additional medicines, all at doses too low. You need to take initially one medicine at a therapeutic dosage, for at least a few weeks. Regimen needs an overhaul, avoiding "piling on."