I did my 45-min. "easy" walk today and I feel fantastic! I had no tightness and felt good the entire time. The warm-up felt good and didn't take too long. My knees were not swollen earlier today and that's a good sign. To help make sure they did not swell up again, I started icing as soon as I finished stretching. Oh, I did ALL of my stretches and they felt great, too. (I still need to find a better IT stretch. I feel it is not being stretched effectively.)
I'm confident I have finally turned the corner. I think I'll start building more muscle and have less swelling and muscle pain.