Bro I understand your problem and position, plz try to understand that you are having a sport injury kind of stuff to your knee, itz jus not pain relief, but its all about why it came. Need to pinch the diagnosis, as far your history loking like, u must be having some acl tear, meniscus tear, or soft tissue injury. Get ur self examined by a orthopaedic or sport experts orthopaedic surgeon. Dun not neglect as knee might not heal if you doin running like this.
Next Steps
MRI would help you to get your diagnosis, but it should be under some expert.
Health Tips
till that tym prevent your regimn of running and take a stops in between like at 1 kms and den rest. If that is also not bearable than do brisk walk till your injury heal.