I realized that the box said only 2 boxes a year. I used them constantly for a year. I have stopped now and brush regularly. My teeth are white now and I hope to keep them that way by brushing solely.
I dont drink pop, coffee, tea, eat candy, or smoke
If you are to follow guidelines provided on the boxes with bleaching strips, well you should be fine.
Did you damage the enamel? It may be a tough question to ask, and one would have to be answered by your dentist during your next visit.
A lot of people seem to over-use bleaching products as they expect to have pearly white teeth. That is not the case though, as how white your teeth may become depends on how white your teeth adult teeth were when they just came out. Bleaching does not make enamel whiter, instead it gets rid of all the stain on the teeth you may have acquired from drinking tea, coffee, soda, smoking and eating foods with color additives. Over-bleaching may even cause your teeth to become see through (pretty freaky sight if you ask me). Thankfully this sort of side effect passes after 24 hours.
Now most of the damage done by bleaching products are to: soft tissue - gums, dentin - located beneath enamel. With recent research I would say that damage to enamel may have occurred, but it would be insignificant to cause any type of serious concern. Still, talk to your dentist and follow those guidelines on the boxes.