I'm a girl and i have a crush on my friend(who's also a girl).and i am scared.please help.?

i am sixteen years old and i go to an all-girls school.In my school,there's this "culture" of juniors will be having a crush on their seniors or the seniors will be having the juniors as their so called "godsister".I thought that is ridiculous.But last March,i have this little crush on my classmate who's a band member.She cut her hair short and she does looks really cool and guyish.Almost every junior in my school band admire her and giving her this admire letters.And this little crush is getting bigger and bigger when she began to comfort me when i'm down and share her worries with me and also when we joke around and stuff.Furthermore,i have this jealous feeling when i saw her hugging another girl and when she begin to be really close with some other girls and juniors(she had a godsister too).I couldn't stop thinking about her,i will feel really uncomfortable when she's not in school. Some of my friends knew about it.I'm scared that one day she will know my secret and worst of all,i'm scared that i might be a bi.What should i do?I tried to get over it,but she's in the same class with me and i will see her almost everyday.What if she knows i like her?Should i deny it?I really need some advice.