highschool drama! how to deal with this?

I’m talking to this boy and he’s such a great guy. We went out on dates and all. He goes to an all boys high school and I go to a co-ed high school. He is on a lacrosse team with boys that do not like me because i was once their friend until I figured out i was just a laughing stock. Today in his school, he told me that they all told him to stop talking to me and is trying to convince him that i’m no good. What do i do?