Too young for this crap

Apparently I have patella inflammation - Chondromalacia to be specific.
Joy.
My right kneecap is inflamed on the underside, causing a rougher surface that rubs on the tendons of my knee leading down from my quads, causing twinges of pain only when it bends a certain way in a fluid motion. Walking is fine, most things are fine...just prolonged bending or going up stairs or (the worst) pedalling my bike will cause random twinges when the bits of my knee that are not supposed meet rub past each other. A few fridays ago I tripped while running. A very minor fall, but I scraped my knee and hit it a bit. It's not clear if this or just randomness was the cause...but now my knee is sore...sometimes.
The best part: there is nothing I can do about it really. I can try and ice it and take antiinflammatories like advil, but other than stretch out a lot and try and find exercises to strengthen my quad muscles, I just have to NOT do anything that hurts it until I feel better...at least 2 weeks. Then I can start back slowly, and in the meantime do things like swimming to increase strength and try to find some therapeutic exercises for my knee.

Joy

The thing about exercising is I like it. A lot. I don't think I was overdoing it, but perhaps I'm trying to do what I'd like to do too soon...this year I've been pretty slack compared to other years so I'm surprised I would cause an injury this year. It's the sort of thing that only happens when you're active...perhaps the inconsistency this year was the issue. Or the tripping-who knows?

All I know is other than going for walks I'm pretty much screwed out of exercising for a while. I've done a bit of reading and it seems that I should be finding certain exercises to strengthen muscles so that this doesn't happen again. I'm hoping a little research will help me find out what they are so I can get back to being active.

I'm only 35- I'm too young for this crap.