Two Corrupted Worlds in 3 Months

Two of my minecraft education worlds have corrupted for no reason over the last three months. 

I have no mods, texture packs or skins installed and there is no link between the two worlds corrupting. The only common denominator is that they both lagged horribly minutes before I lost them, I got several notifications telling me things had been disabled (I caught a video of this if you would like to take a look at these pop ups because I'm not sure what they meant. My friend said it looked like they were telling me the base game had been disabled but I don't know what would have caused that.) Then, eventually my screen went black and I had to force restart my laptop.

Every time I tried going onto the first world, I could wander around for about 30 seconds before my screen went black and I had to force restart my laptop again. I observed that the lag was awful during these 30 seconds and the world refused to load, I could literally fly out to the end of the world and go underneath it. I copied the world, turned off all settings that might have made it lag several times and repeated these steps weeks after the world first corrupted. Nothing worked.

The second world was similar except after a certain point, it wouldn't even load, it would crash my laptop before I could even get onto the world. Also, the memory of the world went up to 120mb and then dropped to 27mb (the original memory of the world was 110mb). I'm assuming this is why I couldn't even get onto the world because the content was completely corrupted. 

I lost the first world three months ago and the second a month ago. Me and my friends worked extremely hard on both worlds and I would like them fixed and restored. 

I can link the worlds to my next post if you want to take a look at them but I sent them to my friend with a high intensity PC and they were even making her PC crash when she tried to access them. So I'm assuming it would make your device crash also.