An entire sea of water can’t sink a ship unless it gets inside. Similarly the negativity of the world can’t put you down unless you allow it inside.
Its not worth your time to allow negative thoughts in. Always try to keep a positive mindset. I know it is much easier said than done. Do things that make you happy if you are feeling down. Go for a walk, talk with friends, spend a day at the beach or lake. The options are there. You are not stuck if you do not have to be. You have people that care about you. Go grab life by the horns!