Sounds like you cut the strings with Duke so I say embrace UMich since that looks like where you'll be going
It's a wonderful campus, my son and I visited last week! I'm sorry you felt pressured to give up on Duke though, I think it may have been premature. Typically these things take time, it's not as though one can expect a decision as soon as the FA office receives a fax from a prospective student.
As an aside - my son received an increase in his merit scholarship from UMich today (he too is deciding between 2 schools though is a different major). In the documentation they were VERY clear that he has until May 1 to make his final decision.