Strengthening Medial gluts

I am currently going to a PT to strengthen my gluts. I see lots of strength training that relys on squats and lunges. My injury is from running. I have a tightness and occassonal pain in my piriformis and hamstring where it ataches to my hips. After I run I cannot bend orver or squat without much tightness and pain. After a few minutes I am better however I am always tight. I have lost all flexibility in my hamstrings. I use balls on my trigger point for the piriformis but have a hard time sitting. I also have a strained ligament on the inside of my knee. I am not able to do any lunges for the pain in my knee. The knee injury has not healed in 8 months. It seems when the knee feels good the hamstring is bad and vise versa. Does anyone know of stretches, strength training anything to help. SInce I started with a PT everything seems worse. I ahve given up any hope of running, I cannot walk uphill and can't even walk very slow flat without feeling a strain where the hamstring meets the hip.

Thanks