Can u help me idk wat to do?

I text my friend Shayla everyday.. We only knew eachother for a week.. And for some reason today she wast textin me.. But I thought she just wasn't getting my text so I kept texting her.. And still no text back so I messaged her boyfriend asking if Shayla was with him bc I really needed to talk to her. But he said she doest wanna talk to me bc I annoy her.. We were all good at school then when we got home ad I started texting she is p.oed idk what to do I want to write an apology or u can help me to tell me what to do.. Shayla is the only one I can trust.. And I'm Like the only one she can trust.. But I'm also a freshmen in high school and she is a junior... I want to keep her as a friend... So can u help me write an apology like what u would say exactly and tell me what I should do? Also there r rumors going on about me that ik she doesn't beleive but idk If someone told her something differently or what.. So I would appreciate it if u help me out