Thought surgery was the answer

Hi Guys! I had an exploratory scope about a month ago and while in there my doctor went ahead and smoothed the cartilage on the back of my knee. He said that it was pretty frayed and thinks that is what was causing the pain and swelling I had been experiencing. I had ACL surgery back in 9/04 and he said the rehab following surgery was probably what did most of the damage although I did have some when he did the ACL surgery. This was my 4th knee sugery (I had a TTT and LR down 5/95, chondroplasty and removal of snyovial tissue in 12/95 (partial tear to my ACL found then), the ACL surgery last Sept, and now this scope. My doctor seemed pretty optimistic that this surgery would relieve a lot of my discomfort and that I would be able to return to an almost normal lifestyle. Here is the problem. I have done everything I have been told to do. I avoid stairs and when I do them I keep my left leg straight, I try not to sit with my knee bent, I have avoided impact activities, I do not sit on the floor or in low furniture, I do not squat or kneel, etc. BUT... I am getting some of the same pain back again. I am at a loss as to what to do. I called my OS's nurse and she told me that it was probably just some irritation because I had the surgery so recently. Everything was going great (I had NO pain by 10 days post op) and now I feel like I am going backwards again. Anyone ever have the surgery? How did it work for you? How are you doing in the long run? I just applied for nursing school and really would love to get this behind me as much as possible. I know I will always have knee problems but just trying to find a way to deal with it would be great. Thanks!