It hurts every time I have sex, and I find that I bleed afterwards as well, what could be wrong?

There are a number of things that could be wrong, it is certainly not normal that you bleed after every time you have sex, regardless of the size of your partner.  While I wouldn’t worry until you’ve spoken to a doctor, I would speak to a doctor right away if I were you.  You may have a problem that is minor and fixable right now, but the longer you wait the worse it may become.