Yeah, I would much prefer the full two years if it weren't for the other factors in play.
Ditch the gf, you're a handsome guy. From what I've heard, the girls come to you
Anyways, I think the point that a lot of people have mentioned, that you don't need an internship, is very true. You've got a very unique background. If you don't want to change careers, ignore the internship thing and go to Kellogg.
However, if you're seriously interested in non-profit, Yale has a lot to offer and you won't suffer a great deal if you choose to remain in health care.