losing saved worlds after PC crash

I came back to my PC and it had crashed: caps lock was frozen and the mouse or keyboard had no effect on the screen which was black. After restarting, I tried to enter my world which I have spent multiple months on and it crashed at once. It affected that world only. The copy version I proceeded to make went down as well. Each time I was kicked out of minecraft. I have lost all of my hard work. It affected 1.15 but it says there are no matches.