I have a hole on my toothe?

its in my 3rd from the right toothe on the bottom row. i dont think its a cavity because its not cold or sweet sensitive but i can literally poke the inside with a toothepick and it hurts lke heck. Also when i eat it doesnt hurt but it does when i brush my teethe. i also have a phobia for dentists >_> so if i need a filling or something will they at least numb my mouth?