hey,
i go to USC too! fight on! the #1 thing you can do is go to SI, every week. seriously, it's a life saver! also, know that it gets better.. bio 220 is, imho, easier than bio 120, and a lot more interesting.
it sounds like you're in thematic option (so am I) so i know you have the brains to do it. honestly, lots of people eff up freshman year; it's where you go from here that counts. i didn't take pre med seriously freshman year either. it just seemed like med school was really far away, and, being in TO, i was overconfident about my abilities compared to the rest of the students at USC. BIG mistake. being smart doesn't mean you don't need to study.
what you should do from here is fix your study habits, ASAP. pulling off a's next semester is crucial, because a sharp upward trend is very impressive. my best advice to you is this, it's what got me through orgo this semester.
-treat school like a job, 9 to 5 or 10 to 6 or whatever hours work for you. focus on school and nothing else during those hours, M-F.
-NEVER bring a laptop to class; it's a huge distraction and your science lectures will probably be online anyway.
-try to schedule long breaks between classes (ie a class at 10 am and the next one at 3 pm). then, avoid going home between classes and carry a bio/chem book with you. if you're not carrying around your laptop, you'll pretty much having nothing else to do but study.
-if you study before, between, and directly after classes, you'll almost never have to study nights or weekends, except right before an exam.
that's just what works for me. let me know if you have any questions about anything else!