i just got my cast off?!

Devin, this is perfectly normal to occur after a cast comes off. The thing that you are going to need now is some physical therapy. They will work with you to free up the adhesion's that have formed. Also work on the opposite wrist first as this will help you to free up the injured one. The more you work the uninjured one the faster the injured one will respond. A therapist should be able to help you with this.

physical therapist

Yes. Presumably you were in that cast for six weeks; during that time, your muscles shrank and tightened up. You're going to have significantly less strength and flexibility on that side for a while. Gently work on the flexibility by just doing everyday activities.

Personal trainer

Broke it 4 times? Yikes! I'm afraid to ask what you do for a living...well...yes it is normal...the muscles are weak there because you haven't used them...it should be usable after a while of time...just keep trying...

EDIT: Oh wait! I saw your picture...you do sports? Well then, good luck!

Your muscles are tight and weak, they need to be stretched out. your arm is also probably swollen and when something is swollen it restricts movement

take it slow, water exercise will help gain flexibility without stress, be patient and let it heal correctly or you will pay the price later