NO DAY BUT TODAY!
I am a fan of musicals - one of my favorites is rent. There is a song called no day but today that contains words I try to live by - "There's only us, there's only this. Forget regret or life is yours to miss. No other path. No other way. No day but today."
Live in the moment! Take notice of the little things along the way. Don't let the negative of yesterday seep into today. Treat today like it's the only day - no worries about the past or the future.