1) If you're a freshman, you still have ~two+ years to pull your grades up. I know plenty of people that didn't do so hot freshman year and still graduated with 3.7+ GPAs. Work your ass off and don't give up.
2) You say you're limited on time. Is that on study time or actual test taking time? If you're having trouble finishing a test the best solution is more practice or more study time until you know the subject so well answering questions is automatic. If you don't have enough time to study, you need to examine your courseload and other activities and see what you can cut. Examine how you study and whether or not it's effective, while you're at it.
3) If you've been taking the classes required for med school (STEM courses) and are consistently struggling to do well, you definitely want to research other possible majors and career options. I don't know much at all about the osteopathic route--I didn't know it existed till I joined this forum 😳 -- but that's something you can look into too.