Minecraft Server Inventory Reset?

Ok, so I have been playing on a nice little factions server called Donut Beam. But, a few days ago, weird stuff started happening. It started when I fell into lava, and I lost my diamond armor and stuff. But then, when I logged off and logged back in later in the day, my inventory had reset to how it was several days before, before I got the diamond stuff. Now, every time I get off the server and get back on, it teleports me to the place a logged off a couple days ago, with the inventory I had the. Now, here's the weirdest part. All the things I've built, they are still there, and everything I put into chests was still there as well, but my ender chest reset. No matter how many times I try resetting it, the faction, whatever, it keeps putting me where was when I logged 3 or 4 days ago, right before I died. Everybody else isn't having this problem, just me.