Will my tooth fall out?

hi,well it could be just a sensitivity your dentist will have to make that diagnosis,if it was the nerve you would be in alot of pain and yes in most cases if a root c is need they just drill la small hole in the back of the veneer,or even if it was needed to be removed you would get a crown,because they become more fragile,so it depends if a post is needed to put in or not of you get a root c,dont worry your dentist will fix the problem,i can understand your worry it might fall out they are expensive and fragile but good veneers last years and years ,they are heavily cemented but even sometimes like eating bread can make one chip off,they can preform a root c on veneers and cover the hole in back,i had one mine fell off i have a crown now,its just more fragile and i had bit something hard by accident,take good care of them everything will be fine tell your dentists all your concerns,and sometimes they come loose because there can be decay underneath so its good to get regular cleanings.