Are you having this problem too? 0_0
Don't worry, it's still there, it just isn't accessible in the gallery right now. You can still find my eight most recent artworks by clicking on any of my art posts and looking at the "You might also enjoy..." box on the left.
Apparently its a known bug, and is currently being attenended to by the staff. Much like you, I panicked when I saw that all my art from this year had disappeared. A whole year of my artistic life, down the drain forever... I know there are a lot of people on Newgrounds, especially the forum, who hate my guts, so I was scared that one of them might have hacked my account or something... But I checked the Help forum to see if anybody else was having this problem, and there were a ton of topics about it there from other users, all of them being addressed by one of the admins responsible for fixing these things.
https://www.newgrounds.com/bbs/topic/1528339
Unfortunately, it means that the artwork I was going to share tonight will have to wait until tomorrow, or however long it takes to fix this sitewide technical issue. Hopefully soon!
On the bright side, now I'm just as shadow banned as everyone else on this site for a change, heh heh!