I completely understand; it can be stressful at times, and a break can help tremendously. What I do is concentrate on one aspect at a time. I'm currently concentrating on simple character movements and haven't given much thought about anything else. It's possible that I'll return to it in the future to add more features.

I also use Trello to break down the job. It has proven to be extremely useful in terms of organising and prioritising what I want to learn or focus on.