Do I have dental abecess or infection?

Hello,

I went to dentist in February got x ray it showed three cavities on my top left gums and a tiny one bottom left. I felt a crack on one of my teeth in top right I told him about this but he said nothing shows x ray. I decided I'll fill the cavities later date. Two week later in late February that tooth where I felt a crack at the bottom with a hole in the middle got a bump above it I thought it's an abscess. I didn't go back to dentist until few days ago due to life reasons. By this time I noticed the one bump became three in my top right gums next to eachother. Also I noticed this hard longer singular horizontal on my left side which doesn't hurt. Dentist touched them said it's just bone. Before February my gums were flat so this is new.I was for sure I had infection I went to dentist he he took x ray, hit my teeth with hammer, used this electronic thing to see if the tooth's dead.

The x ray shows the three cavities on the one left bottom side are the same and no cavities right side where my bumps are. I said the bumps hurt and that cracked tooth hurts. He filled my cavities on the left three of them. But there one tooth also on the left with a hole in it he said it's shape of tooth which doesn't make sense it appeared few months ago. And it still hurts. I also have a enflamed hard gum on my bottom right teeth especially the last teeth one it's hard. These all appeared in the last 6 month. I'm going to endodontists to get a CT scan. Do I gum disease. Also I only brushed my teeth 20 times in the last year and half and flossed maybe only 10 times in the same period (this is culprit I know).

Is this hidden abecess or infection, gum abecess? My dentist suspect it's from the gums. I'm scared it hurts alot especially when I'm brushing my teeth it's throbbing sometimes radiating pain. Is this a fun abecess? Should I go to gum specalist instead? I also feel a tiny hole in my left side tooth cause pain he said my teeth just shaped like that. Should I go to specialist or new dentist?