Sorry to hear about your little one too, Jamie. I have only had luck with one out of three babies that I have bought, even though I have done an infinite ammount of homework and research on them and have 2years experience with my female veiled. I'll always remember when one breeder told me 'Sometimes they just die because it's Teusday.' As in they die for absolutely no reason whatsoever. And that species (hoehnelli was it?) is a bit more delicate than others.
Jacksonii merumontanous is a very very nice species. They do require very high humidity and moderate tempuratures, not high ones. If you expose them to higher tempuratures, or even if you have a heat wave in the summer, it will most likely die or get really sick. Someone I know lost his whole breeding colony (2.6) because of a heat wave one summer, and he also lost all his babies that had hatched a few months prior. Being a dwarf species, they are also quite delicate and I wouldn't recommend you handle them very much or at all for that matter, depending on the individual itself. The males are the prettiest of all the jacksonii subspecies with their aqua blue colours and yellow stripe, and the females are the coolest of the jacksonii's because they can grow a rostral horn. Make sure you are able to keep tempuratures moderate and humidity high before diving into the merumontanous. And a word of caution, if it is wild caught DO NOT accept the offer, it will die I can almost garuntee it, if it isn't captive bred, get a different one.
-Brock