I haven't regularly brushed my teeth since the 3rd grade, am I fucked?

So ever since I was in the 3rd grade (I'm now in college) I have developed a bad habit of not brushing unless I go outside. I don't leave the house much not even for school so I will go days without brushing. I also don't brush twice a day. When I do brush I am thorough. So now I have some cavities that run deeper than I'd like (through feel of tongue), but no pain due to them. My teeth on the inside have a lot of black plaque between them, not visible from the front however my teeth are yellow. I noticed more recently my teeth have been becoming 'white' on the outer edges which I believe is because my enamel is rotting away completely (it's becoming hardly transparent)

Can I reverse this at all or will I simply have to take better care of them and prevent further damage? My breath doesn't stink when I do brush and for bleeding in the gums it does happen when I do brush. But if I brush back to back no bleeding. Rarely I get swelling between two teeth where it leads to some bleeding for a half hour (nothing extreme just lets out some blood if I suck on it) but that's about it.

What are my options for fixing teeth? Will heavily flouridated tooth paste help remineralize my teeth? I heard of crowns but have no idea what exactly those are, will my teeth that have heavy cavities end up getting crowns? I'm scared to go to the dentist honestly. Hate myself for even developing such a bad habit, fuck I'm dumb.