Bachus is absolutely right. Check out the M.S. in medical sciences at UNT HSC. It's one year long and you take most of the classes the first year medical students at TCOM take. In fact, you even take gross anatomy together. Students who attain a certain GPA are admitted straight into TCOM (one of the best, if not THE best DO school in the country). Better yet, students that decide to apply for other allopathic schools in Texas usually have no trouble at all gainning acceptance. I am about to graduate in May and was accepted into my top choice medical school.
This program also includes scheduled shaddowing, an MCAT preparatory course with Princeton review, application orientation and even mock interviews (with the real adcom). It wis a great choice for anyone trying to improve either MCAT or GPA.
If it comes to worse and you decide medicine is not for you after completing the program, there is the option of staying an extra 6 months and updating to a master's in clinical research management (a very good field as I understand it).
oh well, like I said, check it out. I think it could benefit you:
http://www.hsc.unt.edu/Education/gsbs/medicalsciences.cfm