Suggest Remedy For Severe Pain In Knee

i had an acl and maniskus surgury 2 years ago. i some what lied about the pain to play football the following year. after that season i went to the doctor to findout i tore another part of the maniskus. i've been through theropy, not taking it very serious about 6 months ago and now i have severe pain. i've always had a limp, but now its a limp with aching pain. it also has random times when laying down with intense pains, to the point where i'm considering it to be as bad as when i tore it. i'm almost positive i do not have any fractures but its constant pain. i spent a lot of time dealing with the pain until it went away and i completely regret it. please tell me what may wrong with my knee.