Feel Pretty Hard On Knee 5 Days Ago. Very Painful

Feel pretty hard on knee 5 days ago. Very painful first few nights sleeping. Whenever tried to move it or turn over in bed would be excruciating. Pain is not as intense now but cannot bend knee fully when walking. Feels like it gets to a certain point and then will not bend anymore. Can manually move it with hands til it completely bends. My knee cap is also constantly twitching. Pain is in the inner/side of knee.