Any plumbers lurking around?

[SkyBlues42]

OK. So here's my problem. I've been saying for weeks that I'm going to get the hot water in my shower fixed. But, either A.) I'm too stubborn and want to fix the problem myself or B.) I secretly enjoy the cold shower.

I get hot water in the bathroom sink, and all over the house, except in my shower. The cold comes out fine, with good pressure, but when I turn it to hot, it drizzles out and doesn't even get warm.

I don't expect this thread to get a single response, but maybe, just maybe, there's a knowledgeable person in here that can help me fix the problem without having to make an appointment.