What can i do? Problematic lesbian situation?

I am an 18 year old closet lesbian. I am building my confidence to 'come out'. My friend and i have become extremely close recently and i think i have begun developing feelings for her. We joke around that we love each other and leave jokey comments and send texts to one another. She has a boyfriend but they are on the verge of breaking up. I had lost all hope - although there was some signs - that she felt the same way but today she admitted she had dated 2 girls in the past. I felt maybe there could be a slight chance and averted the conversation to a serious one asking if she wanted me to be serious about the romantic things i said to her. She said she didnt want it to make our friendship awkward or complicated and refused to answer me question i tried and tried yet im getting nowhere. I dont have the guts to tell her how i feel. What do i do and what does this mean?