someone help

guys i need help, i think it’s just my anxiety getting to me. but my boyfriend’s ex still contacts his family to talk and “check in on them” and i know how close his family was with her. and he recently blocked her after telling her off and she came crying to his mom saying she hopes he’ll get over this and eventually be her friend. and it’s scary bc her best friend lives two houses down from him and she’s there a lot. i’m scared she’s just gonna keep trying and probably try to come over one day. and in the past he’s left other girls for her. but he’s telling me he’s over her and he does love me, he says and i believe him. it just bothers me she still wants to be close to him and his family. and i know i don’t have the same relationship with them as they did with her. i just feel threatened. am i over exaggerating? or am i justified for being anxious about this? he tells me to not worry but i do i can’t help it..