hmm... to the OP I would actually heed some of the earlier advice and apply to B-school. Try to get into one of the top ones. Its not super stressful and the biggest thing you'll get from it is the expansion of your network which will give you access to capital aka financing to start your business off the right way. That in and of itself is major. From what I hear the coursework isn't all that great, but the networking opportunities are major.
Lots of engineers who make the switch to b-school. Maybe take some time off, study for the GMAT, rock it, and apply this fall/winter. Try to get into one of the big ones, Harvard, Stanford, Wharton. Its not as hard as it sounds, there's a formula. Check out this program:
http://www.ml4t.org/. B-school is work, but IMO compared to law/med school/STEM Ph. Ds, its basically one big party. Honestly, from talking to my friends it seems like a cake walk to me. But it sets you up for great opportunities. Your mindset will change, the way you approach challenges will change and your your opportunities will expand. You just have to make sure you go to right ones.
I understand how you feel, you want to use your youth to make as much headway as you can in your career.