Getting a product to market is hard. It's hard because you have to keep changing the product, adapting to the new realities of your market (if you think your market isn't changing, look again!).
The thing is, it's always going to be hard, no matter how good you are. In fact, the experts are typically the ones who have the greatest capacity to obsess over the details - that's why they're experts.
This is made even harder by the fact that you don't know whether you're working on the last 5%, or actually still 50% alway from completion. (not forgetting that most products stay perpetually at 0%)
The only way forward is unfortunately, the way that nature intended -- Courage, and Luck.