Zoning out is a stress reaction to adjust the brain to adapt the environment which means it is a normal action for us to adjust psychologically.
Besides, it can do good to our health as it can help us relieve the tiredness and get our brains relaxed. I wonder if you feel easy when you zone out as you have forgotten terrible things and just stay in your own world.
It also has its scientific explanation, when you are zoning out, your bood circulation can be improved so that can provide plenty of oxygen and nutrition and help relieve tension and anxiety.
Therefore, if you feel tired, you can just give yourself several minutes to get out of mess and just stay with yourself.
Hope that will help.