Blowing one day of your plan is a pothole. Blowing the next day too is turning off the road.

A single miss changes nothing except the count. What does the damage is the second one, because two in a row starts to feel like a description of who you are rather than an accident. The gap between one and two is where most abandoned plans actually end.

When you miss, put the next session on the calendar before the day is over, and make it small enough to be certain. Do not try to make up what you lost, since that usually produces another miss. Getting back the following day is the entire skill.