So, I'm playing along, and then hit F11 to hit fullscreen, right?
Then Minecraft just up-and-crashed on me, where I sat there befuddled.

I expected Minecraft to resume like normal, and I would be able to play on osu!craft like normal.

If it's any relevance, I am using a 720p resolution HDMI screen [1280 x 720 if I remember correctly], and am running the screen off a laptop whose native screen size is 1366x768 [though the screen is damaged, thus the necessitation of the HDMI screen].

Attached is the crash report. You may wish to console the launchers sometime in the near-future.