Slow progress is better than no progress
Being productive is being able to do the things that matter in the shortest amount of time.
It's about time and timing. There is a window of opportunity to execute a task. Delaying it indefinitely will not be productive at all. It's about doing it while it matters.
Is also about progress and accomplishment. About walking towards a Vision. Those are the things that matter.
The concept of building a Vision may feel daunting, but really it shouldn't. A simple Vision could be set towards improving your health, your business or your fitness habits.
So you can set yourself to start with something simple you can do everyday such as, starting the day drinking a full glass of water.
Doing it every day, at least for a month, will build discipline within. You'll be making a slow progress, but nonetheless, a progress. You also can start doing a pushup everyday, no excuses, for at least a month. You can start tweeting about your business once a day (or every other day). Just commit yourself to it. You can build upon these habits.
The tasks that lead you to the Vision you set for yourself are the ones that will make you feel moving forward and thus more productive. Doing this for a while will make you more disciplined, more resilient to the "I don't feel like doing it" feeling that makes us all fall back.
Once this barriers are broken, things will start piling up. You'll start figuring things out.
I know this method is uninteresting, will demanding and generally unappealing. But it's easy to start and to follow through. The rest is on you. You have to set yourself for it. You have to want it. Otherwise you'll just remain in the same place.
Just take your time. You know yourself, be realistic and start slow - even if you're full of energy right now. Think long term and how to manage in the low energy days.
Set a low energy mode strategy: keep a set of prepared tweets to send in busy days, do only a pushup instead of ten when you feel exhausted, but by all means keep the pace.
Avoid making drastic decisions, specially if you know you'll soon go back to it. Break it into small to achieve steps. Make it fail proof. Focus on consistency first.
And always remember: Slow progress is better than no progress.
And when you start seeing yourself making progress in general, you surely will feel way more productive in life.