I've read a load of books on happiness and spirituality and none of them seemed to click like the book I'm reading now - Solve for Happy by Mo Gawdat.
They say you need to meet the right teacher sometimes to grasp a concept. Mo Gawdat has been that teacher for me. Hopefully he will be for you too. His back-story is heart wrenching.
Below is a YouTube intro. summary of the book. If like me, you struggled previously with some concepts within the spirituality/happiness sphere, I urge you to read this book (or listen via Audible like I am). The concept of our thoughts not being us is explained in easy to understand terms. Think of your brain sending emails to yourself that you can either disregard or act upon if critical - you don't need to identify with your thoughts, and you are the boss of your brain not the other way around! The song by the Dub Pistols - Running from the Thoughts also sums this concept up too (I urge you to listen to that song after reading the book!)
Stay safe and well.
Peace and Love.