I’ve been waking after about 4 hours of sleep. Then I’m awake, usually until time for the alarm clock to go off, when I’m ready to go to sleep again. The following day just KILLS me, then I sleep all night the next night, then normal for the rest of the week. The last night of my weekend, I lather, rinse, and repeat.
Hate it.
Maybe it will help, if you go to bed earlier.
If you know you’ll be awake in 4 hours, have something productive, but boring to do during those couple of hourse. I’ve heard reading is the best thing for combatting sleeplessness.