Bad luck
I don't know what to suggest other than check the autosave folder.
since CC 12.2 by default Ae saves your project every couple of minutes (the default is 20 unless you changed it - I set mine to 5) and since 13.7 it saves by default when starting the render queue. these are fail safe mechanisms of of course as you should always remember to save your project from time to time. that's why there's the handy increment saving. I had cases where I close to 100 versions in the same folder _1 _2 _3 ... in addition to auto save!. this is what you learn to do after this stuff happens. and still I can find myself going into a project and forgetting to save for the first time! which will make the failsafe auto-save not work at all because I have to first save the project... but enough about me. how about you? whatever it is, if it's gone - you will make it better next time! and you learned a valuable lesson.
live and learn I guess.