Do not go to bed if you are angry.

Try to sort out problems so you don't have to think about them after you’ve gone to bed. Even if you manage to fall asleep, it's not uncommon for your mind to start spinning if you wake up in the night, which can make it difficult to get back to sleep. Another way to deal with negative thoughts is to write them down in a diary. 

WHY IT HELPS:
Worry, anger or resentment can cause stress reactions that increase cortisol levels and make it difficult to fall asleep. Instead, by staying calm and relaxed, you help your body's production of melatonin – a hormone we need to fall asleep and stay asleep.