Eyal, I'd cosign what's been said above about seeking professional help. Um, that came out sounding a bit more personal than I meant.
But step back a bit even more than that. First you should probably learn about what you don't know; I understand that potential founders are coached to be super-confident and project "I know it all", but it seems you aren't aware of what really goes in to design -- which is problem solving, not just making pretty images/elegant look and feel. You mention that you think your UX is "outdated". Why so? What makes you think this?
Also, you don't mention user research at all. There's an incredibly high correlation between not doing user research and vanishing into obscurity (I've seen it over and over again (self-promotion of something I wrote, and make sure to read the comments: http://boxesandarrows.com/we-dont-research-we-build/). People often misread "Lean Startup" as meaning "start building immediately", but Eric Ries never said that -- his rapid build/test/iterate cycle comes after gathering data on your hypothesis. That is to say, you need to treat your "vision" or "idea" as an hypothesis, and test with real people you don't already know whether this solves a problem that people who are not you actually have. This saves so much time and money, as changing code is harder than changing your angle of attack.
So, when looking for a UX designer, please keep in mind that a good one will ask at the onset, "What problem does this solve, for whom, and how do you know this?" A good UX person is not just there to pretty up a visual design, but to make things really work for real people and real problems -- and this may involve challenging you on your assumptions.
And we all know what happens when you assume, right?