Help me choose a contraceptive?

I am currently a freshman in college. My parents are very religious. Also I am suppose to be "the most successful and pure child." My older sister is on BC due to the fact my parents believe she's too ignorant not to get pregnant. With me, however, there is no way of me getting on BC with my parents help. My boyfriend can not stay hard with condoms and I'm not on a form of contraception. Any form of contraceptives I can use that is not the morning after pill? Or how could I get a form of contraception that works extremely well without using insurance? How much would they cost? Please help