Throbbing knee pain that hurts to sit/lay down? Help

It depends. Knee pain can be caused by patella chondromalacia or internal derangement. It can also be referred from an occult hip or lumbar spine problem. Try vmo exercises & nsaids. Persistent pain calls for an x-ray and evaluation by a healthcare professional.
Knee pain. Consider inflammation, injury to cartilage, meniscus, patella, overuse, etc. Also consider referred from spine (disc herniation, etc.).