I went through this same thing with my first start up.
Plan on spending 2/3 of your money on marketing. Only 1/3rd should be used to actually build/test/etc your product.
You should be worried about how the app or product actually works. Don't do the marketing yourself. If you know how you want to market it, that's fine. If that's the case, hire someone to just take orders from you. If you don't know how you want to market it, hire someone that can utilize personal connections in the field you are in.
It is simply not possible to program, secure funding, bug test, bug fix, and market all yourself.