I hope this doesn't come across as poorly stated, but I would highly recommend looking into possible dietary causes. I don't mean you are eating like a slob, but rather you are eating something which you are not supposed to eat either because it is too processed for your body or it is an allergen. Tooth decay can be cause by the diet you are consuming and if you are not consuming the correct nutrients( bioavailability is based on your genetics and not just the source of food)
To add to this, sugar/sweets aren't the only thing bad for your teeth. Other less obvious things like bread or pasta are terrible for the teeth. Basically the "simple carbohydrates" group of foods.
Also acidity matters, try to keep it neutral like water/milk. (things like coffee or wine should be avoided).
Brushing times can also help and always floss at least daily.
If you're interested in learning more I would check out the teethtalkgirl YT channel. It's a great way to learn a heaps about teeth without paying $$$ at the dentist asking questions. (but you should still go to the dentist)
Anyway, that's my 2c, best of luck, teeth are the worst.
