When I started, I was 87lb overweight, so up there close to you.... I hurt a lot too. My knees, my hips, my back, my feet!
I don't disagree with the folks saying you should see your doctor (although I didn't haha), but I'm telling ya, get that weight off and you'll be amazed at how much better you feel and how many of those pains do go away.
Start slow, but don't be afraid to push yourself a little. I was convinced I would only be able to do a slow walk and water exercise for the rest of my life, and I'm 40. I quickly found that a good walk would actually make my knee pain better. And within a few months, the pains were gone. I went from walking, to jogging, to kickboxing and Insanity.
I'm so excited for you to find Sparkpeople!!! Follow this plan, and you're going to see big changes!