Should I confess to my crush?

So I’m an 11th grader, and I have a crush on my friend who I’ve known for 3 years, and I’ve had it on and off during that whole timeframe. Right now it’s been going strong for like 7 months.

For a long time I’ve been able to keep it lowkey. Shes had ghosting phases before, where she stops talking to me online and in real life both while seemingly being ok with everyone else, and those have hurt a lot and I’ve had to be really persistent in getting her to communicate with me when they happen. It’s usually because she’s going through something, and I always end up cutting her slack because of how much she means to me.
Even in daily life she doesn’t reply to messages at all, but I’ve grown used to it by now. It’s just she does.

For some more background, I met her in 8th grade, a time when I was really self conscious (still am but even more so) and I didn’t really have anyone who “got” me. She was the first person I met in a long time, and first person in my new school who I was able to call a “best friend”. We used to stay up having conversations, sending music to eachother.. good times. One time she tied my shoes on the basketball court. Man. Ok enough sweet nostalgia

There have been times in the middle where due to some typical middle school drama I stopped talking to her for some time, but at the end of the day I always end up finding my way back to her. She’s the funniest, prettiest, most open minded and most relatable person I know.

There’s also a caveat where she has this guy best friend she’s really close with, and a lot of people suspect that they’re dating. Nobody really knows. She always swears that she isn’t, but I don’t know. So there an “other guy” in the equation who makes it hurt more.

For so long it’s been possible for me to keep it all buried inside me, but these days im really burnt out. I see her face in every girl I see, I can’t keep her out of my head for even a second, I keep spiralling at night thinking about what if I never have her. I have 2 years until we split off for college, and honestly I’m incredibly scared at the thought of her slipping through without anything ever happening. I know if I ask her out I’m probably gonna get a no. My friend group dynamic is probably gonna get weird.