(Concern) Slight insomnia

There are many reasons why I can't sleep well. I worry about work unnecessarily. Also, although indirectly, I often don't turn off the lights properly. I stay up late watching my phone or YouTube. Sometimes I don't turn off YouTube either. As a result, I wake up in the middle of the night after falling asleep. When I wake up, it's often hard to fall back asleep.

It's not severe insomnia, but a bit of insomnia. What do you all do when you wake up in the middle of the night and try to fall back asleep? Anyway, I sleep alone, so I can do anything I want.