I have sensitive teeth. Sensodyne only numbs the nerves. How do I repair them?

I have sensitive teeth with a lot of enamel wear probably related to acid reflex which was untreated for about 2 years (couldn't afford the meds for a while). Anyway, products like Sensodyne only numb the nerves. They don't help repair damage to the enamel, or allow the teeth to repair itself. What can I do to help my teeth grow stronger?