Bff choosing boyfriend??

So my bff since fifth grade ( we are juniors in high school now) got a boyfriend. Okay whatever I’m happy for her. But am I really? I have known him for longer. He likes to smash.. a lot. and she’s not like that. well i found out the other day that the third day they were dating, she already sucked his dick and he ate her out. ON THE THIRD DAY!! at school, we always walk to class together and meet up and stuff. every since she got this boyfriend, she would come up to me and say ‘ I’m gonna sit with him’ and then she would go and sit with him. I got my license last week and I haven’t even told her yet!! she was gonna be the first person that I told. I’m not controlling or anything. If anything, I act happy for her. but it’s like she chooses him over me. I already told her how I felt and she kinda just brushed it off, idk. someone tell me some advice