Take therefore no thought for the morrow: for the morrow shall take thought for the things itself. Sufficient unto the day is the evil thereof. – Matthew VI, 34.
Those words are taken from the Sermon on the Mount. Simply, they mean live in today only. Forget yesterday. Do not anticipate tomorrow. You can only live one day at a time and if you do a good job of that, you will have little trouble.
Follow the link, try the 24hr plan. Start today not tomorrow whatever it is you want or need to do. Just start and be surprised at end of day where you have reached. Start again following day and as weeks, then months pass you will get there. Even if sometimes you fail then just start again. Too easy to use possibility of future failure as an excuse to not even try. Today encouragement to climb the mountain to enjoy the view, at my pace, one step at a time.
Have a good day