Nettan,
Your plight sounds very dire, indeed. For one with such complicated problems and deep knowledge of his/her own condition, often it is helpful to schedule an appointment with the doctor performing pain management functions to indicate that the situation has changed. It certainly sounds as if an escalation is taking place, and I urge you to seek highly specialised medical advice.
Please let us know how you get by. I'm very sorry I have nothing to offer. You might do a search (particularly in the patello-femoral section) and see the types of alternative remedies that people use for pain relief. I'm not aware of the impact your nerve damage would have, but many people speak highly of TENS units on various settings, ultrasound, warm baths, capsicum creams (maybe not this one!), emu oil, lidocaine patches, taping, braces....the list is quite extensive, and I'm just paraphrasing here from earlier posts. If the oral pain medications aren't getting it done, you may want to see about alternative treatments (always monitored by a physician).
Take care and keep us updated.
PFS Mod