Does ketamine treatment actually provide some releif. I am a cancer patient who was left with nerve damage after an operation?

Maybe. Ketamine is an anesthetic agent which may be useful in some chronic pain conditions, such as crps (complex regional pain syndrome). Usually given as an infusion in subanesthetic doses over several hours, several days in a row, usually by a pain specialist or anesthesiologist.
Yes. Ketamine is a pain medication that can treat pain through nmda receptors, unlike drugs like morphine that use mu opioid receptors. In other countries, a "ketamine coma" is being studied. I have seen it help patients with very difficult-to-treat pain, though it is not a miracle drug and has side-effects, especially at higher doses. Consult with a pain management specialist for all your options.
Yes. A ketamine patch can be helpful in some chronic pain patients. It is not always a good choice because some people have bad dreams while under the influence of ketamine.
It can. Unfortunately, ketamine is not used often. There can be side effects and oral dosing is available only through compounding pharmacies. It may be worth trying at 5 mg every 4-6 hours. Talk to a pain specialist!
Possibly. There is a wide range of pain treatments available, and ketamine can be a helpful medication for some people. There are a large number of narcotics for pain relief, as well as other oral medications like Neurontin (gabapentin) for nerve pain. Cancer pain often requires stronger treatments including nerve blocks and/or nerve ablation techniques. Cancer pain requires multi-modal theraby by a pain physician.
Doubtfully . Ketamine has been suggested as effective in cases of intractable chronic regional pain syndrome (crps). It has to be administered in hospital due to multiple side effects. Pain related to a surgical nerve damage should be probaly treated by different medications and/or nerve stimulation.