Where did my disc space go?

To start, I am fairly new at linux. I bought a 1 GG Ram 25 GB droplet to host a small game server with about 5-10 friends.

I installed TightVNC and a docker program for Neverwinter Nights Enhanced edition. I know the latter is taking up about 500 mb. I do often log into a cloud drive to download new maps to play on, and promptly delete the old ones. These are about 50 mb each.

I was rather surprised today to learn I had only 30 mb of disc space left. I the following and learned that 21 gb of space was in var.

cd / && sudo du -h --max-depth=1

I see some of that I cannot even access as root. I am guessing its infrastructure on your end. Is there a way to see when all this space might have vanished? I am purchasing backups. I am not sure if they are being stored somewhere and eating up my space? Or if possible I can load a previous backup where I hadn’t consumed so much.

Any help would be appreciated.