How can I overcome negativity?

I agree, negativity seems to be the initial reaction for most people...and in my experience overcoming it is less of a quick fix and more of a life long work in progress. I find that affirmations and practising gratitude really help! If you have never tired doing positive affirmations I suggest reading books like "You Can Heal Your Life" by Louise Hay. Filling your mind with positive thoughts can naturally crowd out the negative :)

Hi! Thinking negative thoughts is really our human nature. It's our choice if we want to be happy. I suggest you smile in front of a mirror every morning before you start your day. Tell yourself "It's gonna be a good day." I mean, everything is in your hands. Be happy! Think positive! If you are positive you will attract positive in your life.

When you feel stressed, breathe in and breathe out. Close your eyes and block everything that comes in to your mind by imagining you can see nothing but just a white color. Do it while doing the breathing exercise.

Remember that you are too busy being happy and positive.