Unlock Queen Bee and Astute as soon as possible, and focus on only having sex with the groups that give you double SP. Always say yes to second round of sex. Otherwise focus on studying. On day 14, use accumulated SP to get enough energy to study until A+
Same logic applies on the latter half. Focus on group project first (you can advance with high addiction too, so no need to masturbate), and start studying only after you've cleared gp.