Hi, I Am 36 Yrs Old Male. I Feel Click

Hi, I am 36 yrs old male. I feel click click in front/ top of my leg near pelvis bone. It happens when I fold or unfold my leg. It causes pain when I stay stand for long. I can't open my legs properly. I also feel pain in left hip. I feel a knot in my left hip as if some vain has a clot.