I had TKR and I have to tell you recovery was long. It was at least 6 or 7 months before I could really bend my knee. It is essential that you take the pain meds, do the exercises diligently several times a day, ice after each exercise, and don't worry that you are using your walker. Keep walking as much as you can. Mobility is important. And forget about the doctor. His job was to fix your knee. Now if he did a bad job, that's a reason to look for someone else. Do you have a primary doctor that you can talk to about your pain or neuropathy concerns?
I hope this helps.