Crush and best friend

So I've liked this guy since the 5th grade. (I'm in 8th now) and we started talking again about a week ago. So, we were really hitting it off until my best friend came in and asked me for his Insta account. I gave it to her and we started a group chat. Little did I know, they were pm'ing while we were in the group chat. They like each other and I'm so heartbroken because I've been trying to get him for so long but then she just came in and now they keep flirting in the group chat. What should I do? :c