PC [HELP] Lost Progress on Steam Running on MacBook Pro

[Kyroka]

This has been an issue for the past three days. The other day I went to play my game and it had jumped me back to Day 5 when I was on Day 7. The next (in real life) day, I took the advice of a Reddit response, and turned off Steam's "cloud synchronization". I then played the game, exited to title, and it had saved the progress. I also backed up the file (or so I thought, I'm not very tech savvy). Today, it did the same thing again, though my multiplayer host files are up to date.
I tried going through the Missing/Corrupt Save File Guide on this website. However, I got stuck on making a diagnosis when the guide says to "Open your character’s save file (File #1 above) in notepad (it might a few seconds to load)." I'm assuming it's the coding source Notepad++? If so, I'm unable to download that on a Mac. My own fault for owning a Mac and not a Windows running computer. I'm unsure of what "notepad" means.
I'm also having trouble finding a way to not rely on Steam's saves. I've been reading a lot, and many people have problems with lost saves while playing SV through Steam. Is there any simplified guide to being able to save files to the PC directly? And how does it work, would it affect my multiplayer files? I haven't found a good solution to any of this. I've even read that people give up on playing the game because of the amount of times or work they lose.

 

[Kyroka]

Update: I made a copy of that file in the Saves folder. I then played on both files on SV from Day 5 to Day 6, selling parsnips on one of them to differentiate between the two. After playing on what I assume was the copy, the other file had backtracked to Day 5. Basically, whenever I opened a different file/game, the original game would lose all progress. So. My original file was corrupt I'm guessing? Anyways, copying the file in the Saves folder worked!