Speady, here is what I think your problem is, please correct me if I am wrong.
At one point, you attempted to play Yogbox. It tried to update, and you clicked yes to the optional update. After that you entered a vanilla Minecraft world, and your mods were all deleted. Some mysterious 6 months passed and you attempted the same thing with Tekkit, but you did so by clicking the Technic button, but here you don't seem to have any issues at all!
No, this is a failed attempt at a bug report.