I know it is easy to say looking in from the outside..but I still say there is nothing like your own business. You are not feeling anything that all business owners haven't felt at some point in the process of owning a business.
I admit--it is not for everyone but if you have an entrepreneurial spirit, it is hard to get the satisfaction you want in a large company although it does sound really good at times....The problems you are dealing with now will likely look small as you would look back..just an opinion not knowing all the facts but I always encourage people to dig in and keep moving..be glad to talk to you sometime if that would be any help to you.