In the very beginning of my sobriety, I was told time and time again, "Take it day by day". It never made any sense to me. I would always think to myself, "A whole DAY!? I'll be lucky if I make it through the next HOUR!". There are exactly 86,400 seconds in a standard 24-hour day. It takes a split SECOND to grab up that addiction. Why day by day??
For an addict, "a day" can feel extremely long and daunting. I encourage you to face each second with strength, and your minutes, hours, days, months, and years will stack up more graciously.
Even your "I've only been sober for an hour", IS an accomplishment!! When you go to bed tonight, pat yourself on the back and remind yourself that you made it another 86,400 seconds! 

