Rebel, sorry to hear about the bum knee, I have a pair of those myself. One thing I can tell you for sure is that my knees are a ton better now that I weigh a lot less. They still hurt, but it's not crippling pain anymore. My right knee has been taken apart and reassembled twice, the left is slightly better and is still in it's original state, gnarly but functional. Have you discussed using anti-inflammatory meds with your doctor? Mine has me on a daily dose of 1 Alieve and 1 low dose aspirin. I take both at night right before bed. I've been on and off Alieve (or in the family of Alieve) meds for a long time, but when I added in the low dose aspirin, that made all the difference.
The other thing you might try for the soda is a flavored water, you might as well replace the soda with something you need anyway right? Just today I tried Propel Zero, peach and it's very yummy. Normally I don't really care for flavored water, but this stuff is almost addictive. I used to drink close to a 2-liter bottle of Diet Coke every day, but now I use Diet Coke as a reward for getting in all my required water. But I'm thinking about switching from Diet Coke to Propel, yummmm....
Starting weight: 244.6 lbs. 10/01/09
Pounds lost: 80.6 lbs
Current weight: 164 lbs
Goal weight: 120 lbs
Weight to go: 44 lbs
Goal Date: 1/1/13