To many days we spend thinking negatively. We let life and it's circumstances take our joy from us. We need to learn to look past all the negative things going on in our life. I understand you may be going through some tough times, but there are just somethings you cannot change.
So why not choose to be content. What I mean by that is you can't change these things, but you don't have to be miserable about them either. Maybe God is waiting on you to you see all the joy he has placed in your life. Then maybe just maybe once you make the change in your attitude, God will make some changes for you.
So instead of being unhappy about the things you don't have, find joy in the things you do. Stop letting life pass you by with that sour attitude. Happiness is a choice, so find a reason to smile each day.