At ASU they have a thing were you take classes again and you can replace the new grade in place of the old grade for up to 18 hours. Of course I'm transferring next year so my wife can start dental school, so maybe the new school will have something like that. If my grades aren't well still.
AMCAS (the application service for allopathic med schools) doesn't recognize "academic restarts"--they count every grade you ever got, even if your college doesn't. They have a whole handbook of rules and regulations about filling out the application, and it says multiple times that they don't recognize grade forgiveness, erasing grades from transcripts, etc. So if you retake a course, BOTH the old and new grades count toward your GPA.
However, as a previous poster said, you're not in too deep a hole with only 8 credits to your name. If you do well from here on in, you should be all right. HOWEVER, you must be sure that you really are ready to take school seriously and stay with it. If you're not, you're just going to be wasting your time and money, and you won't get into med school anyway.
What is it that has caused you to become interested in medicine anyway? That's an awfully demanding career for anyone to go after, much less someone who has had serious trouble with school in the past. Does the fact that your wife is going to dental school make you feel like you have to keep up with her achievements?
I'm not saying you don't have a right to want this, or that you can't succeed at it if you are very determined, but I'm suggesting that you think long and hard about whether medicine is really the right career path for you. It's a huge commitment of time, money and effort, and not something you want to enter into lightly.
I think it would be wise to get some medically-related volunteer experience under your belt as soon as possible, to give you some exposure to the day-to-day realities of health care so that you'll know what you're getting into. If you do like health care but don't want to take on such a heavy-duty academic burden, maybe you could become a PA or nurse practitioner instead. Just something to consider.
If you do decide to go after medicine, I think you'll be able to overcome your rocky start if you really apply yourself. Good luck.