Ouch! I did the ligaments in my knee in a long time ago and couldn't walk on it and ended up in plaster ankle to hip to stabilise it. I'm not sure if it's what craft means but I remember them sticking a needle in my knee pre plaster and much I don't mind needles, OMG!
When my knees etc...are swollen up (inflammatory arthitis) I tend to get the tubigrips out though I don't keep them on for too long at a time (and not overnight), if you keep them in the fridge they are nice and cool when you put them on. I also use anti-inflammatories and try and keep it raised, easier with ankles admittedly but if you lie down and keep your knees up (shove some pillows/cushions under) it might help. Bit late for an injury but if it helps it might be worth a try.
Be careful you don't damage it further it end up with it being a weak spot, it's not an emergency but if the fluid doesn't shift, get it looked at.