advice, please.

so i just turned 15, and i have a wonderful boyfriend who couldn't make me happier than i already am. but I'm very afraid of what i've done. i had never had any sexual relations with anyone. never had someone touch me innapropriately, never even had a proper kiss. but he came along and later on in the relationship we started doing things. i was fine with it, but i told him that i ABSOLUTELY DID NOT want to have sex. one night, things got heated, and he got on top of me and tried to get me to have sex with him. i said no, but he begged me and continued to beg me until i said yes. as soon as he started, i began to cry because of how bad it hurt and told him to stop, but he didn't. he kept telling me "it's okay baby" and didn't stop no matter how much i asked him to. eventually he did because i repeated it over and over again, but he was mad at me and himself. i don't understand what i'm supposed to do. he seems happy to be with me, but only when we have sex (which i worked my way into.) i feel like a complete failure because i can't make him happy. i have no one to talk to about this, and i'm terrified. please help.