If you scored all "A"s on the AP classes, get a 33 on the ACT then you have a shot. But you state many things that give me pause like your teachers didn’t prep you well but you only gave yourself 2 weeks to improve your current act and your a procrastinator.
These will not lead to success at Michigan. It’s an extremely hard /challenging school. Lots of students drop a full grade the first semester /year.
Saying that. Apply and consider it a reach school. Have other schools that you might be a better fit for also. Good luck!