How Long Does An Injury In Calf Take To Heal?

I,m 58 female. I fell hard last night while chasing my dog. Landed on left leg. Immediate pain in left upper calf. Had to sit for awhile because of pain. Hurts when I don't try to walk. Extreme pain when try to walk. Dragging around with severe limp and pain. How long to heal? And what to do & not do? Thank you.