I think my knee is sprained?

My left knee is swollen pretty badly, but it doesn't hurt, only if I like tap on the knee cap.

I can bend it without it hurting, but it's just really stiff & uncomfortable.

I went jogging three nights ago, & went to bed completely fine, but woke up with it like how I just described it.

Yesterday it started to pop a lot, but the popping didn't hurt at all. It actually felt good.

What do you think I should do to make it heal fast? Or could it be completely broken? Ahhhh help.

Thank you!