Ive been through this too, I got a crown and 5 new fillings last year because of it (also damage from bruxism they refused to diagnose for 3 years) Best advice i can give is avoid much sugar/carbs because that feeds the bacteria that causes decay and swish some water after eating anything. Also remember brushing even for 30 seconds, mouth rinse, anything, is better than nothing. Drinking tons of water also mitigates the bacteria by preventing dry mouth