I hate waking up during the night and not being able to fall asleep again

I know the feeling! I think it happens to everyone sometimes.

One recommended "treatment" is simply to get out of bed and go and read something easy-going until you feel drowsy again. Don't try faffing about on a computer, phone or whatever though. Those tend to keep you awake.

Sometimes I drink a cup of hot milk, and that seems too work for me.

Yeah same. Very annoying