Maybe pick a different exercise. Like, if you don't have time to go to the gym, but you can walk to the store for grocery shopping and carry back your purchases, do that - it's two birds with one stone. Or if you're close enough, walk/cycle to work. Personally I tend to do better with exercise when it has a goal.
And I agree with the one day at a time thing. Stick to what works for you for the most part. The biggest thing is that it is WORTH IT in the end. You'll be effing thrilled that you stuck with it, I guarantee that. You won't look back and wish you'd done something other than exercise.
Good luck with everything!