App crashes at random tines.

Long story short, I had five sheets opened. I was opening a sixth one (I usually have eight or nine opened) and the app crashed...in the process deleting my five hours worth or work I was doing. I went into the app backup and recent files and none of my work was saved (It never crashes and when I close it by mistake, I can restore the session). This time I restored the session but my work was not saved...AT ALL. Is there some genius thingy I can do in order to get my files back? Some kind of operation to do? Because one of them is a gift to my mum that I have been working on it for months and I really need it because I do not remember anymore how the piece goes lol. I mean, I only remember the two main themes but the variations are forgotten. Please help me. Let me know if you have Teamviewer just in case you need to see for yourself.

Thank you!