The world was never supposed to be opened. It was only opened because the mods were taking so long to get updated, but it was never an intention to open before the mods because of how many problems would arise. This is one of them. If you don't want to lose hard work, I'm sorry, but don't work hard O.o At least for now you can get a feel for 1.9 and when the mods come out you'll be better prepared. Seriously, where did people get the impression that anything was going to be carried over?