I would agree with the others in that you have a great start on the lion and if I were in your place I'd strive to finish it. You've gotten some good suggestions so I won't post more.
I will say in response to Rahul that everyone paints (or rather, creates) differently. I cannot focus on one block at a time - if I do, I lose all sense of the painting and it's done for. I invariably end up throwing these away. I always work all over, bringing the painting to completion at once (not section by section). Everyone works differently so do whatever helps you focus.
I did want to comment on coming back after a hiatus - it's a bugger!
I took a year off painting about 4 years ago and it took me several paintings to feel as though I was back on my game. I got "rusty" in my time away from the easel and the only way I recitified that was to PAINT
So be gentle with yourself but keep at it.
I also like Jason's suggestion to mix up working on small and large paintings - I also do this and it really helps keep my interest going. I'll also throw in some plein air painting to spark some creative energy.
Best of luck!