Okay so i was doing my normal Bicep Workout

3X8 sets of Barbell Curls
3X8 Sets of Preacher Curls
3X8 sets of the weird reach for the sky curls
(Start with a preacher bar and slightly less weight than you use for normal preacher curls and curl from a down position, with your elbows stationary, up to your chin and return to down position, sorry i don't know the exact name for the exercise but it works.)

ANYWAY, I do the sets in reverse order, the reach for the sky curls first, preacher, then barbell. On the second to last set of Barbell my forearm started hurting something fierce, the part right above my elbow where that big vein is. I pushed through it figuring it was just normal workout stress, but it is now several hours after the work-out and its not just a dull ache, but a more piercing pain.

Has anyone had this happen to them before? If so, what causes it and how do you make it go away?

You are experiencing tendonitis. Many people experience this when they do barbell curls. In fact, BB curls are a terrible exercise for most people. I suggest that you stop doing them and switch to using DBs.