I Recently Got Friend Zoned

Getting mixed feelings from my crush. A while ago I told my crush how I felt in a letter, her response is in one of my old posts, the letter starts "Hey there." But any way, it has been a little while since that happened, but now things seem to have changed. Last week she finally reached out and responded to one of my emails, she gave me her new email address so we could talk more, then I emailed the new email and I got her number from her. We have been texting almost everyday since then. She is as nice as always, but there just seems to be something there, it's hard to explain, but there is something. She is and has always been one of my closest friends, I was her first friend in high school and we are in band together. If you want any more background than read back into my experiences: she is the clarinet pla<x>yer who I had eaten lunch with and was really nervous to tell how I feel). Please help, sorry for such a long experience, but I really need some help with this.