Every time i try to open this drawing I'm working on, Krita just crashes and says that a problem has caused Krita to stop working properly. My dad says that it's probably that my file is getting too big or that it's a bug in Krita, but I just don't know. I REALLY want to be able to finish this drawing, because I'm almost done and it took so many hours!

Hi. I would suggest you to fill a bug report. But before that you can do some investigation.
[*] You can try to increase max memory allocation in Settings-> Configure Krita -> Performance -> Memory Limit.
[*] You can try to open you document in another computer, especially if it has a different operating system.
[*] You could try different versions of Krita - try 3.2 Beta, if that does not work - try older 3.1.x and 3.0.x.

This way you would have some more insight on what is the problem.
And take this as a lesson for your drawing process - to keep versions of your drawing as you progress. Krita has a special option for it: File->Save incremental version or File->Save incremental backup.

Hi Inkus. I'll try some of the stuff you suggested. Thanks! Also, though, I do want to tell you that I didn't lose all my progress, I did save everything, I just can't open it and finish it.