Problems don't come from the world outside of you, they only come from how your mind reacts to the world. But it's very tricky because ...your mind projects a captivating story which makes you think your feelings come from people and circumstances outside of you.
In reality, what you experience only comes from how your mind AUTOMATICALLY interprets everything outside of you.
When you believe that your feelings come from the world around, you use all of your energy to control the world, trying to get things "just right".
But you can't, ever, control people or circumstances ... so that approach will never solve problems permanently.
When you understand that your painful experiences come from how your mind reacts, then you have the power to resolve your problems, because your mind is the only thing you can actually control ...
... and it's a LOT easier than you'd think!