Im no doctor, but the place you pin point on photo looks like de quervains tenosynovitis, had it very recently so I know what you are talking about when you say sharp, intense pain. Recently has been being called '
blackberry thumb'. Happen when you over use the extensor and abductor tendons of the thumb (extension position on the pic below), causing thickening and inflammation of the tendon which causes pain trying to pass through the synovial fluid compartment. Basically the tendon does not fit in the compartment, the added friction will increase the problem.
It is similar to carpal tunnel syndrome, although it in the 1st compartment of the wrist.
How long ago has it started? And has it been getting worse?
My opinion, go directly to a hand specialist surgeon for a proper diagnostic and treatment, if its tenosynovitis ask for a injection of corticosteroid into the sheath of the first dorsal compartment. It will fix it in 2-3 days, although if you don't stop doing what caused it it will come back and probably need surgery.