What Causes Shooting Pain In Thumb ?

This morning & all today my thumb pain is horricl HORRIBLE I JUST WANT TO SCREAM.. its my right hand, and its my thumb that hurts, all around my thumb down to the start of my wrist, and if I touch my middle finger it shoots pain in my thumb, its a constant pain, but it becomes sharp and extremely uncomfortable if I move my hand at all. the majority of the pain is on my thumb like at the base of my thumb I guess it would be considered to be my thumb NUCKEL, if I touch that from the outside OMG.. its bad. What is this and WHY is it happening & what do I need to do I cant even lift my kids or anything that would require both hands