I grinded my teeth as a child and wore the tops of my teeth down. Is there any way besides crowns of fixing them?

Not really. If you had them built up with standard material they would break very easily. Once you grind them all away then full mouth reconstruction is your option for treatment. You should be wearing a night guard to reduce the damage you are causing becuase most likley you are grinding at night still, most people do to some degree. See your dentist for optoins.
Not usually. Only other option is removal of the teeth and replacement with implants and crowns. Direct resin fillings will not hold up. Crowns usually best treatment. See a prosthodontist (specialist) for an evaluation before making any decisions. They are specially trained in this treatment.