There is nothing wrong with getting borderline passing marks, or even withdrawing from courses. I've had to and It's hard to accept that "failure," but I had to relearn the skills of writing papers, studying for tests, and managing your time. In addition to all that, I have your disorder to cope with.

School is hard! Still, the only real reason to worry about marks is to receive scholarships and get into grad school. Some of us are just really bad at demonstrating what we have learned, or have had that learning affected by something.