I'm A Paramedic. I Picked Up A Large Pt From

I'm a paramedic. I picked up a large pt from a seated position. As I lifted I felt something tear, like pulling a muscle, in the back of my l knee. Right between the 2 large tendons. I hoped it would heal but it's been about 2 weeks and no relief. Pain in the affected area and pain throughout my knee. Lots of stiffness. Ibuprofen seems to help a little. Thanks Ted.