Modded items disappeared from inventories, chests, and the world map

[Nebham]

I run a tekkit server for me and my friends. Yesterday morning when I launched the server, I tried to log in but it kept booting me out instantly. I noticed that the problem was that I launched the wrong .jar file, and I launched the vanilla minecraft server .jar that comes in the file folder. When I launched the tekkit server .jar and logged in, everything from my inventory that wasn't modded items disappeared (red matter items, tools, ect.) As well as all buildcraft pipes, the quarries were reset, and all of my industrial craft machines were facing the wrong way. Every item that was in a mod chest (ender chest, iron chests, ect.) was just gone. All of my EMC in my transmutation tables was gone. Every modded item in vanilla chests was gone. Needless to say I and many others on the server lost a lot of stuff. Is there anyway to get this stuff back? Is there back up data somewhere that I can recover? Or if I didn't make a back up of the world then I am out of luck? Did this happen because I loaded up the vanilla server and log it or was there another problem? Thank you in advance for anyone helping to make sense of what happened and how to move forward.

[JaariAtmc]

You didn't make a backup of the world, you are out of luck. You loaded the vanilla server which overwrote all the modded stuff.