What the heck?

[theonlychicken]

I finally created a Hexxit world where I got set up without dying because of something ridiculous.

However, while in a battle tower, I seemed to have pressed something or something happened by itself, which either rolled back my inventory to yesterday and gave me my old normal diamond sword and iron armor or maybe it switched my backpack for my main inventory for some stupid reason.

Any way to reverse this, considering my backpack is gone, or what?