Thanks for your question and sorry to hear about your pain. But why did you have that knee surgery? Moreover, it is not normal to have so severe pain after surgeries. Symptoms as you say suggest that something is wrong somewhere. It is better to go back to your doctor for further checkups. It is something unfortunate that cortisone injection and pain killer have not worked for you. I think you might have developed some complication in your surgery or got some new injury while surgery. Get medical support as soon as possible, if possible from the old doctor itself.
Get well soon.