Frankly, too many people have horse apples for brains. Why do you think that is? To misuse a verse in the book of Proverbs, "For as he thinketh in his heart, so is he". What are you putting into your head? Crap? Well, plants need fertilizer to grow with, but your mind is not a plant.
My father was fond of saying that your mind is a garden. Plant thought seeds, water them and see what grows. If you plant good seeds, you get good results. The opposite is true as well.
I tend to think that the mind is more like a computer. Any programmer knows that a computer is only as good as its input, which is GIGO: Garbage In, Garbage Out. Also, you need to have good programming in the first place, or even the best input will give bad results. Too many software vendors do not test their products thoroughly and rush it to market, and then have to issue patches and revisions.
A simple way to show this is when you use a search engine. If you want to know the annual rainfall of Monterosso al Mare, you do a search for that, not for meteoric dust levels in Antarctica, capice? If the search engine is poorly programmed, you get bad results.
If you want to know how to think properly, you have to have good input. And you need good programming. What does that come down to? Fill your head with good thoughts, positive things, reasonable input, logic.
What's that on the television? Death, destruction, rampant sex — hey, quit watching my TV! Then check your attitude when you walk away. One-sided, biased news broadcasts? No wonder you think like a mindless sheep! Music about death, hate, suicide? Downer. (You already know how I feel about rap "music", that's the most negative and hateful nonsense I know of.) And music is extremely powerful, because of the repetition and concentration. What are you friends like? Do they uplift you, or are they negative people that bring you down, psychic vampires that sap your energy?
My advice to you is to break away. Get decent input so you can have control over your mental processes. (It only follows that your emotions will be influenced as well.) Branch out. Meditate on good things, on truth, on balance. You'll see and feel the difference. See for yourself.