The glass is half full, not half empty. Be thankful that you have a glass.
There are so many people in the world who are less privileged than you.
Who can't sleep peacefully at night. Who don't have a roof to protect them from the storm. Who are forced into labor, marriage or slavery. Who can't walk. Who can't feel. Who are blind, even though they can see.
Be thankful for everything you have. Be content. You don't need much to be happy.
Eat. Sleep. Repeat.