Category “Filling”

Hello Doctor, I have a problem and need your advice. My filling in my back tooth fell out a while ago so i just have one edge of my tooth there now. For a while it hurt after i ate, now it doesn’t hurt me anymore but now there’s something red inside is it my gum? Also how will this be solved. Will i have to have an operation? if i do will they give my something to be put to sleep whilst they are doing the operation? How do i get my teeth back in good shape? just by brushing everyday. If i brush more than twice a day does that damage my teeth? Any feedback would be greatly appreciated, Thanks.