Good for you, CherryRed! You should be proud of improving yourself. Don't be hard on yourself for losing "only" six pounds. When a person lifts weights, it builds muscle, which puts on
good weight. So you've likely lost more than six pounds of fat.
Since you are already lifting weights and doing aerobic exercise, and you say you want to get in shape faster, may I recommend
Body for Life. I've been on it for two and a half years and love it. It's made me really fit and I'm never hungry. The author, Bill Phillips, has a very encouraging tone. It gets results pretty quickly, too.
I hope this doesn't sound impertinent, but have you looked into all possibilities to help your knee, including supplements and acupressure/acupuncture? I know people who find glucosamine/chondroiten helpful for their joints, as well as people who have found relief with acupuncture.