Vibration in quantum physics means everything is energy. We are vibrant beings on certain frequencies. Every vibration is equivalent to a feeling - there are only two species of vibrations, positive and negative. Any feeling makes you broadcast a vibration that can be positive or negative.
Every thought emits a frequency to the universe and this frequency goes back to origin, so in the case, if you have negative thoughts, discouragement, sadness, anger, fear, all this comes back to you. This is why it is so important that we take care of the quality of our thoughts and learn how to cultivate more positive thoughts.
Gratitude is so powerful, and positively affects vibration frequency. Start to be grateful for everything, for the good and the bad.