Check out http://www.forbes.com/sites/bruceupbin/2011/10/18/paul-graha... for encouragement or go and get a co-founder.

Being a solo-founder, it's a tough ride but no-one said you shouldn't go tough. But also I keep in mind that in order to be a full stack entrepreneur, one needs to be able to attract talent and you need to have a sense to filter out wimps.

Sadly I'm the only founder right now but for one specific reason - to spend time building product instead of dating founders :) But I sure wish to find the one, or two.

Final note regarding solo founders & YC: if you are coming from a non-US country without a working visa and need to move to US to work for your startup then having at least 2 founders is great because then the company has the power to fire you -- which makes it possible for this new company to apply for your visa.