project not opening

My computer was being really slow so I saved my project as a project file and restarted my computer. I attempt to open it back up to resume working on it got the computer telling me to use the File>open command even though that was what I was doing.
I searched around to figure out what was happening and got nothing. I didn’t mess with the two file parts so it’s not that one file is in the wrong place. Is there a way I can fix this? If not is there a way I can prevent it from happening so I don’t lose days of work again?
I’m using 2.3.0

I suspect the problem is that your computer was running so badly that it didn’t complete saving the project before you rebooted.
Do you know why your computer was running so slowly?

I think it had just been running a long time and needed a quick reboot since besides this hiccup it was working just fine afterwards.

Has this been a one-off problem, or has it happened again since?

First and only time it happened.

I’d suggest that for now, make regular backups of your work (in particular, after recording, export a backup as a WAV or FLAC file before doing anything else).

Okay I’ll do my best to remember to do that. Thanks for your help