<p>Personal issues do make a difference and can explain your HS stats, but if you’re applying as a junior transfer, they won’t care about your HS stats that much, your college stats will matter a lot more.
I don’t think you’re being stupid or pretentious, you’re just a hopeful freshman (like me) who is dreaming of transferring. Find some EC’s at USC related to your major/interests (I don’t go to USC so I can’t give you specific clubs, but I’m sure you can find out). Pick 3 or 4 EC’s and dedicate yourself to them. Lab research is a great plus for a pre-med majors. But I’m not saying make all of your EC’s about your major - Med schools (and ivies) love well-rounded students, with interests other than Biology. If you dedicate yourself to EC’s, you might be able to gain leadership positions - like President of the Biology Club or something, I don’t know…find something! EC’s not related to your major are great too if you dedicate yourself to them (put in time/effort) and show interest. Quality over quantity, always. 4 EC’s are more than enough. You have 2 years ahead of you so good luck.</p>