Simplify your mind.
Your physical life is nothing but an extension of your mind, so if you want it to be simple, start by simplifying your way of thinking.
Have you ever noticed how you spend most of your life making it more complex?
In your pursuit of being someone, you entangle yourself in life by trying to build a higher degree of sophistication.
It's the natural effect of the mind striving towards mastery and exploring the different ways to get there.
Mind overflow
As such, there is nothing wrong with it. It's a phase you have to go through to learn what life is all about, but it does take its toll on you.
Over and over you experience the consequences of the complexity you have established, and it all ends up in your mind.
You have to deal with it on a daily basis, and at some point the mind overflows. That's when you decide to simplify.