One of the hardest parts is getting started. I already mentioned that. So where do you go from there? There will always be doubt. Self-doubt. Doubt in the process. Doubting your progress. Your intentions, your objective, your performance. Seldom is anything safe from that disconcerting nuisance called doubt.
But doubts can only stop you if you let them. They can't always be ignored. Sometimes they need to be embraced. Acknowledged. And then promptly disregarded. We have more important things to do.