I Have Sever Pain In The Back Of My Thigh

I have sever pain in the back of my thigh with visual bright red veins and black and blue bruising. Ive had this for almost 5 months, been the the e.r. speacialist and they keep telling me its my sciatic nerve and i am worried i have blocked veins can i have blocked veins. I cant move after sitting or laying, i hurt while im sleeping and if i am active it hurts and i limp but not as bad as laying down