ugh, I'm going to be brutally honest here.....
I don't think many people could handle anything remotely close to what you are trying to do. It is quite a load. You are planning on studying for the MCAT prior to taking any organic and physics 2? Big mistake. In fact, I made the mistake of taking physics II and cell bio during the summer while I was taking the PR class. Although I got A's in both the classes, my mcat prep suffered. and you are planning on doing this ONTOP of retaking 1 or 2 classes that you got D's in.
If I were you, I would retake both of the classes that you got D's in. I would wait until fall and take classes like Ochem I & II, and physics II during the semester so that you wont feel rushed and can really focus on learning the subject matter. I would lightly prep for the MCAT with some prep material and take the kaplan prep class next spring, preparing to take the MCAT next april/may and apply then.
Honestly, you need some GPA repair, and just think, by retaking 1-2 classes and taking a kaplan course, what if that hurts your studies in Ochem or Physics II and you end up getting a C or D in one of those courses. Then you would be back at square 1....