The knee is badder

Crap. I've never really had knee injuries before and this one ain't getting better. The good news is that as a massage therapist, I learn a lot from my own injuries and therefore it seems I will now add a new skill in my massage therapy practice: the knee.
It's not the ACL, It's not the LCL, it's not the illiotibial band so what is it? I could still run on it this week. I can walk and swim. There's no swelling. It's just a nagging dull pain whenever my lower leg is not supported and I need to make slight twists with my foot. The thing is I don't want it to get worse, or chronic. What to do, what to do... I'm fed up of icing (got an ice pack on the joint as we speak...). At first I thought it was a problem with the Gracile muscle which turned out to be really tender. Something's up and I don't know what it is. I did Pilates today as my training. Swimming was fine yesterday but I'm supposed to run tomorrow morning...