Some people just do not have the ability to quarantine as effectively as others. You are left with a choice of never getting a new animal, or just QTing as best as you can.
If/when you get new animals, always be especially careful where you get them from, look them over very carefully before you bring them home, etc. Also, look into other possibilities you may not have considered. Do you have a friend who could QT your new animals at their house? Even if it stayed at their home for only a few days, it would be better than nothing. Normally, I'd say an animal you got from your friend should still be QTed when you brought it home, but a friend that has no other reptiles would seem like a reasonable QT location if you have no other options.