How can I replace a world I accidentally overwrote?

I used to play on my own minecraft server with a friend using Aternos minecraft server hosting. My minecraft partner and I have sadly split up and went separate ways. This happening i decided to download the world and continue playing it as a single player world.

When i dragged the world files into my saves file it automatically replaced some files on a different save and copped over some files. My friend and I played a one block survival world together through downloading the world and uploading it to the servers data. Joe and I wanted to stop playing the Skyblock and play a normal survival world, the one I was having problems with.

Me being me i wanted to continue playing this Skyblock world by myself. So i downloaded the world and started playing it. But then when my friend and I stopped playing i saved the world download to my own save files, the files of that world went onto the Skyblock world, causing endermen not to attack you. I was wondering if there was a way to get my world onto a normal world file and not this one block skyblock file.

If you need me to clarify anything i can totally do that. As this enderman thing is nice to have i feel like I’m not living the normal survival experience and difficulty. Thank you for any help.