I think 'ruined' is too big a word, since that suggests that it is permanent, while I think that at least the majority of your negative feelings will be temporary.
If I understand correctly you feel more comfortable without the belt now, but you also feel guilty for not wearing it, because of your idea of keeping pure. But once you have truly made up your mind about what you want, most of the guilt will disappear.
If you decide that being fully chaste is the way to go, you won't have the guilt anymore. You will keep having moments where you get frustrated, but if you are truly convinced that you want to stay chaste, you can live through them, and afterwards feel proud that you've kept your resolve. (Of course that is easier when you the belt is on and you can't get released.)
And if you decide that this keeping pure is not right for you, you won't have the frustration. But if you are truly convinced, there won't be true guilt either, although you might still sometimes feel regret for not staying pure.
With the two in-between options I mentioned in the previous post, you might have something of both, but less intense.
Personally I feel that, since you don't want to wear it to school and other outdoor activities, the constant on-off will keep giving issues. And after school, when you go to college, it will probably get even more complicated, especially if you move out, e.g. to a dorm. (If you can't find a solution to keep wearing the belt then, would you feel bad if you had been trying to stay chaste until then?)
