ready for sex

I told my boyfriend I wasn't a virgin when we first started talking because it wasn't a big deal since I didn't think it would ever go anywhere. we have been together for 6 months now and he keeps trying to have sex. we tried one other time and it hurt really bad so I just told him I wasn't in the mood. What do I Do? I feel comfortable enough with him to do it, but how do I make sure I'm good at it? I feel bad for not pleasuring him. and why do I bleed every time he fingers me?