Working with Patients who had amputations

Hello, I just wanted some advice in regards to dealing with patients with amputations. The other day, I had my first experience with them. My patient, Mr. X had a history of leg ischemia, prior fem-fem bypass and peripheral vascular disease. He already had his right leg amputated and now, he came into the hospital with a persistent pain in his left leg (most likely from his poor circulation because his foot was a purplish red colour). I know that the biggest thing is pain control, but it doesn't seem to be working.... How can help this patient deal with that and then still health teach about activities of daily living?