It burns when i pee and it itches badly?

I am already past the std age , dont have that problem , but it burns so bad when i pee I feel like i will pass out , usually this happens when i wear tight clothing, one reason , and i dont drink alot of water, but i do drink water more than i use too, But i dont have access to a way to get to a doctor no car and i live way far out of town... anyway any ideas would be great