My wrist is throbbing no fracture or tendonitis. what do you think is wrong?

Many factors: It depends on your age, history of trauma, and other medical conditions to name a few. Categories of the cause are trauma (sprain), arthritis, raynaud's syndrome, carpal tunnel, drug reaction, and infection to name a few. This really needs a proper exam and evaluation. Ask your doctor if a referral to a hand specialist is appropriate. Hope this helps!