300 pound fatass here.

So I started hiking this spring to lose weight and do something for my health - I hike every saturday or sunday about ten miles and lost about 15 pounds just through hiking.

But here comes the problem: I recently got problems with my right knee. When I walk, everything's fine. But after I sat down for a while, it starts to hurt. When I get up I need several minutes until the pain ceases and I can walk like a normal human again.

At first I just had it the day after hiking. But this week its still lasting although its already thursday and I'm a little afraid that my joints are waving the white flag:

I'm fat since I was a kid (34yo now). I know that all the extra weight is not good for the joints, but is it possible that the walking made it worse?

Any tips how I can fix this? Because I'd rather be dead than stop hiking. I really love the shit and need it - aside from the weight loss, I really found a hobbby.