Lost storage while deleting windows 10 drive on BootCamp

I was using both Mac OS and Windows 10 on my system. My MacBook is 2011 model. Anyways, Windows 10 was running out of space and had some virus issues. For this purpose I wanted to increase my space and reinstall Windows. I went on BootCamp for deleting windows. There was an error but BootCamp windows drive wasn’t showing in finder and on BootCamp. When I check my Disk Utility it also showed no other drive and my Mac OS’s drive didn’t showed any increase in storage. Therefore 60GB is missing. I also checked my BootCamp is I can still change booting is to windows but I couldn’t. What should I do ?