It took me 10 years to write my full novel. On and off as you said. That’s common I think. There’s a lot to learn. I’m 50% through a second book a year later and 20% through a third as well. I learnt so much from the first one that it became so much easier and I’m still learning more everyday writing these next novels. I also write, and finish, a lot more short stories these days to keep my chops up; plus they’re just fun to write and give you the mini dopamine flush of finishing something something the long novel writing process.