In a way, you're in a great position in which you can make a real difference to your business. While your partners have to go on every day with the same programming tasks, not always able to see how they make a difference in the immediate term, you get to wake up every day, consider what's the best thing to do right now to advance the business ... and do it. Sometimes it will mean working on funding, other times it will mean filling different roles for which you're not yet ready to hire an extra person (marketing, sales, user support). Sometimes it might even mean just getting out of the way and making life easier for the developers (someone needs to cook those ramen - make sure they're delicious).

I think the main problem you have (I can only imagine, I was never in that position myself) is that you need to remain very confident that you're pulling your weight. Do that by deciding to not worry about the division of labour and simply doing the absolute best you can all the time.