Claiming that you want to accomplish vague goals (i.e. "I want to eat healthier") doesn't give your mind a clear schedule to operate by.
Your habits need a time and place to live in your life.
Want to get back on track with your writing schedule? 9am on Monday morning. Butt in chair. Hands on keyboard. That's when this is happening.
Want to exercise? Give yourself a time and place that it needs to happen. 6pm every Monday, Wednesday, and Friday. I'll see you in the gym.
The bottom line is this: it might be nice to tell yourself that you're going to change, but getting specific makes it real and gives you a reason and a reminder to get back on track whenever you slip up.
Soon is not a time and some is not a number. When and where, exactly, are you going to do this? Do you have a system in place to automatically remind you to do your new habit?