My forearm hurts while lifting?

I've been working out for two months now and recently while trying to lift heavier weights my forearms hurt. It's not just during curling movements, it happens even if I try to grip heavy weights for dumbbell chest presses and even during shrugs to the point I just can't hold the dumbbell. I don't think it's an injury. My forearms actually become pumped and stiff during these periods and it stops hurting after a few minutes of letting go of the weight. This sucks because I know I have to lift heavy to get bigger.