Hello, about a month ago something was up with the gap between the last tooth and the one in front of it. it felt like as if i had something hard stuck in between. So i tried picking at it with a toothpick and nothing seemed to happen, so then i tried floss...and still it felt like something was stuck in between. and finally i took the dentist pick and started to pick at it, i guess i did it too rough because a part of my tooth cracked off. Now i am left with a cavity that hurts when i try cleaning it with a tiny brush or pick. It also gives off a bad cavity smell. I dont know what to do, I know i need to get it examined asap but i am afraid that the cavity is so deep that it hit a nerve and i may resulting in a root canal.