lost 5lbs this week

I have lost 5 lbs this week with eating better and doing a lot more exercising. I have a lot to lose, I have to stay focussed to get back into good shape.I will continue with what I am doing, I rode my stationary bike for 30 minutes although now my knees hurt, I will walk today. I know my weight gain does not help my knees although I have a condition called ankylosing spondylitis which can cause severe pain, even when I was thin I had chronic pain......I just need to keep on stretching.