what the heck is this on my leg? its been there for a long time doesn't hurt and its not on my other leg

Maybe type 2 diabetes.
Supposedly slight lower leg discoloration is a symptom.
It is not going to hurt or anything.

Though at your age and weight, I have a hard time imagining it is diabetes. Even if it is, pretty much everyone has it so whatever.

Ask your doctor.It could have been a leaking blood vessel inside your leg that discoloured the skin.Don't check on google it's just leads to panic.Chances are all is well and over time the the discoloration will fade away.