Thoughts are magnetic, and they have a frequency. As you think those thoughts are sent out and they magnetically attract all like things that are in the same frequency. Everything sent out returns to the source. That source is YOU.
Like the Law of Attraction. Think of yourself as a magnet, that magnet will attract to whatever your thinking.
This is what I've read. I try affirmations myself and if I feel bad (thoughts) I try and change my thoughts. When you feel bad, you are on the frequency of drawing more bad things to you. Change your thoughts to something good, that makes you feel happy.
Put on a piece of music, start singing, that will change your emotions IMMEDIATELY.