I need advice!!

I’m in grade 9, my best Friend hates my boyfriend and she turned all my other friends at school against us and I now have no friends except 1 person. Well no girl friends except that one person. But even the guys are starting to turn on me. But there is nothing wrong with my boyfriend, he treats me like a princess, he treats all my “friends” good, he treats all his friends good and he treats my family and his family good. It may be because he is 1 and a half years older then me but I don’t think that should Matter to any of my friends. It’s getting really annoying.