Way to go on starting c25k. I waited until after the winter thawed to start the program last year myself, so good on you for hitting the new year hard.

There will always be a "next Monday", but do you want to be in the same position when it comes around again? Of course not. But in some areas, like running, you may be (c25k does repeat time/distance ran vs walked to not build up difficulty too quick) but you are certainly not in the same place in other areas. Even if you are not able to run on a day, what about a shower? Making a healthy treat for yourself?

I guess my point is even when you are feeling like one item on your plan seems impassable, look back and consider the small things that you haven't given yourself credit for. I would think I had had a "zero day" where I had done nothing, but brushing my teeth and moving from my bed to the couch and dropping food into the dog's bowl was my victory for that day and while I was aware that I had not achieved all of my goals for the day, I still put in some work for myself down the road and it helped keep my gaze in front instead of at or behind my feet. Don't let anyone else define your victories though.

Thrash on, metal mama!