Just a few tips that have worked for me to get me back up when I'm feeling really sad or angry, or am just having one of those days. They really help! :) BTW: I know I'm playing with a bobbypin and some of you may not like it, but I was trying not to gesture a lot with my hands, like I tend to do.
To listen while using other apps, switch the player to Picture-in-Picture (PiP) during playback — it keeps playing in a small floating window (the screen stays on).
To listen with the screen fully off, in-browser playback stops by YouTube's design. Open the video in the YouTube app to keep listening where background playback is supported (e.g. with YouTube Premium).
Open in YouTube app