Friend with benefits

So I was away on a school trip to Poland this weekend and my ex boyfriend was there. We broke up a year ago but for about 6 months he's been asking to be 'friends with benefits'. We often do quite sexual things and despite us both being underage, he asked me to have sex with him. I responded no, 1) we had no protection and I am not an irresponsible person and 2) I just don't want my first time to be with someone who doesn't love me. I'll get one thing straight, I do love him and have done for a long time, but he doesn't feel the same about me and he only wants anything to do with me when he's bored and can't get anything from another girl. So when I said no he continued to try to persuade me and tried to take my underwear off and picked me up and tried to pressure me into sex. 2 of my friends knocked on the door and he immediately stopped but what scares me is what he had the potential to do because he's very strong and knows I love him. I love him and it was only after I spoke to my best friend afterwards about the incident when she told me how wrong he was and I'd just like some advice please xxx