Lost Progress to Mine Craft world

[Crypted_data347]

Hi! I created a new mine hut server today for me and my friends to play. It was survival. We spent around 4 hrs on the world. before we started playing in the world. we were going to set it to hardcore, but when we joined the server, the settings are not the same way i made them. We got off the server and i was going to shut it off. I was going to check onto the server, but now for some reason the world looks different and i do not have my stuff. Also the settings that we added earlier, were now in the server. I thought that the server might have been overwritten. Although im sure i would have received a warning before i applied my settings right? Is there a way were i can retrieve the old server world? Or could some one show me how to fix this? 

[_Tarna_]

Do /worlds. It should show a list of all the worlds you have on the server. Your stuff might be in a different world. To teleport to each world, you can either click on the world in the list or do /world [world name].