I Am Confused About My Feelings

I have a huge, overwhelming crush on my female boss. I've only ever had relationships with men and the thought of being with a woman had never crossed my mind until she came into my life. There's just something about her that I can't put my finger on. She's an amazing, strong woman who makes me laugh, really supports my work and she listens, really listens to whatever it is I'm saying. She was there when I was going through the breakup of my last relationship, always had an open office door for me with coffee and tissues if I was upset. I don't see her support any of my colleagues in the way she's there for me and I know I'm not imagining it, we have a great relationship. I just don't know how far to push it. We have many a late night email conversation, always entirely innocent but with a flirty undertone if you know what I mean. She's single and has never been married. She's about 15 years older than me and whenever I see her around our workplace I get butterflies and a big smile on my face. When I sit next to her in meetings I can just smell her perfume and feel her close to me. She's in quite a senior position compared to me and I'm pretty sure nothing would ever happen but on the other hand I want her to know how I feel because there's a part of me that suspects she feels something between us too. Argh.