I have weak enamel. You get your teeth from your parents. If you have weak enamel there isn't anything you can do once it's gone. Nothing you eat or drink or do makes any difference.
I worked with a young man with Down's Syndrome and his parents would punish him over and over and over for not brushing his teeth 3 times per day. They would literally come into his apartment and lock his TV. Really!
He had perfect teeth. No bad breath, no valid reason to brush 3 times per day other than mom and dad wanted him to.
I took this young man to about 8 different dentists. The parents wanted a dentist to tell him he had to brush his teeth. Every single dentist took one look at his teeth and told him he never had to brush his teeth again and he'd still never have a cavity. Ever. He could eat anything he wanted and toss his tooth brush and toothpaste.
This really made the parents mad. I asked each dentist why brushing wasn't important in this case. Every single one of them said you have the enamel you're born with. Not much changes what happens with your enamel. Either it's strong or it's weak. If it's strong nothing can hurt your teeth. If it's weak there isn't anything you can do to keep from getting cavities and losing teeth to fillings, root canals, extraction, and more.
If the enamel is weak on your teeth there isn't anything you can do except talk to the dentist about caring for them by having more appointments with him/her throughout the year. Your dentist might have some ideas but it's usually just keeping your appointments every 6 months and not putting off ANY work that needs to be done.
If you let a cavity slide for even a few months it's eaten to far into the tooth by that time and the tooth is gone. If there's a cavity or even a spot they think might be turning into a cavity they need to be proactive and fix it as soon as they're sure it's in need.
Otherwise you might end up with a lot of caps or even false teeth in a few years.