A lot of people Don't realize that the mitzvas weren't given for 40 or 90 or any other number of days at a time, it's not that you either stop doing something for an X amount of days or you lose everything,
meaning there's a big movement that everything in Yiddishkeit needs to be done for 40 days in a row in order for it to be recognized as something done, and that makes people think that if I fall through in-between 40 days then I lose everything I have worked until now.
But you have to realize that if you kept strong for 10 days and then you fell through, the past 10 days didn't just go away, you're still getting S'char for the 10 days you did keep strong, hashem doesn't look at 40 day charts, he looks at every day as its own, and every single day you keep strong even if you fall through the next day, every day is a struggle for itself and so is every day a win for itself.
So, remember to never forget the days you didn't fall through, the days you did keep strong, and celebrate your wins because nobody can ever take that away from you. and never stop trying because a strong day is yours forever!!!
Have a wonderful week!!