Knee pain

I was on my long run this morning and I had no issues on the run itself, however, immediately after stopping, I had very intense knee pain. I can’t walk without a limp and any sort of bending or rotating my knee hurts pretty bad. I’ve never dealt with any knee pain or injuries before this. The pain is coming from the outer part of my knee and shooting to the front bottom of my knee. I’m not going to run until I can at least walk normally but I would love any advice to help me navigate this injury!