Have you considered a part-time MBA? This might fit your needs to keep working on your start up and at the same time working towards your MBA degree. Although I

Have you considered a part-time MBA? This might fit your needs to keep working on your start up and at the same time working towards your MBA degree. Although I don't know your life circumstances, in general I would not recommend leaving a successful company. If you look at the MBA graduates many try to do what you do right now: start and run a successful business. UCLA and Berkley for example offer great part-time MBA programs.