OP, my story is not so far removed from yours so I get where you're coming from. In your shoes, I'd say apply now. The retake isn't worth it and you'll always be told that your chances are "low." Not that it's a false statement but you're a well-rounded candidate IMO, that's already been accepted once before. SLU might even give you a favorable, more "expedited" review. Keep that MD list as broad as possible (despite the limited pool) and throw just a few DO schools in there. Keep chugging along and best of luck!