Attitude is something that keeps one alive or dead. Laugh out loud because dead here represents the life which has no excitement, negative thoughts all around and depression.
All you have to do is find ways to maintain that positive attitude in life which will keep you smiling at every turn of your life, in every situation, however hard it might be to face.
Yes, you already are, try to keep yourself occupied with work rather than just browsing your way through Facebook and Twitter. Keeping yourself fully involved in doing chores which keep you happy, takes away the opportunity for the negative thoughts to creep in.