My left testical hangs lower and the scrotum skin is very loose which makes the the scrotum hanging much lower.then left skin hangs much lower which irritates.please help?

This sounds entirely normal. In almost all mature males, one testicle hangs lower than the other. (Upscale tailors even have a turn for it, in tailoring trousers: "Do you dress right or left", meaning which side his testicles hang -- usually the side of the lower one.) But if you continue to find it bothersome, perhaps a urologist could tighten things up with minor surgery. Good luck.

Tightness of the scrotal skin depends on many things like cold, stimulation etc. Sometimes dilatation of the veins (varicocele) can make the left testicle lower. If worried get checked by a Urologist. In the meantime wear a good supprt underwear. I think you will be OK