horrible tightness in hamstrings

[FUZO]

I have no idea why my hamstrings are so damn tight. I do everything possible to get flexibility. What could cause no flexibilty. Could it be bad hips,lower back what. When I get my epiduril injections in my hip joints and lower back the hams loose up but I dont know why. Its been geting so bad that I can train my kick boxing anymore. I cant kick or I'm in pain the next day.The pain is in my lower glute and hamstring. I cant bend over if I do I get a very shar pain