I understand your position. I graduated from college and worked for several years in a different field prior to going back to college to finish pre-requisite courses for dental school. It was a long road but I wouldn't have done it differently. I'm not sure what NC and W mean but it sounds like you may need to retake your biology courses. Your chemistry grades look decent, so they should be fine. If you really want to pursue dentistry don't worry about the timeline so much. Many people change careers and directions throughout their twenties and beyond. Be grateful you recognized this early! If you do want to pursue it I would finish your remaining required coursework and double your efforts. Treat your education like a full-time job and you will be successful. You are also in a really good position to do well on the DAT. If you take a whole year of post-bac courses your science education will be fresh and prepare you well for the exam. I would just try to take the courses at your current college, or any other convenient school, and get them done. Good luck!