Friend zone bullshit

I have a good friend of the opposite sex. We have been cool for around 19 yrs. We once started to be involved but somehow we did'nt. We still talk on the phone and hang out. We both know I have feelings. I left them alone for years. I accidently begin to ttell her how I felt and that turned out to be a mistake. I shyed away, not wanting to ruin the friendship. She let me down kind of easy. She continued to call me saying things like we are like brother and sister. The only problem with this is she forgets we are like brother and sister sometimes making highly sexual comments like I can't handle her sexually. She has a boyfriend of 7 years well sort of...she is his side chick. I have a girl too. 5 years ago I spent the night and we almost got it on. She sent me to get condoms but when I returned she chickened out. I have lately stopped acting like her brother because she always gives me mixed signals. She gets me talking about sex but goes back to the brother sister shit. I stopped calling and answering her calls. I work out now and stepped my appearance up. She started calling wanting to hang out more lately. She had started inviting me over more sending sweet texts and acting more unsisterly. i spent time with her let her know how I feel with out being direct. She was all smiles. This is where problems come in. In our entire 19 year relationship we always have something to talk about. The last time we were together though was different. I was too afraid to talk to her and her to me. We just sat watching tv while she would not get of her droid playing bingo. I sat there for an hour and we maybe said 5 words too each other. I felt nervous as hell. The tension was too much and I left. She didn't call me the next day like she does like clockwork. 2 then 3 days passed. She didn't contact me on my birthday this is a first. I contacted and asked if I did anything wrong because she hasn't called as usual and she said she stopped calling me because I hardly answer her calls...which is true. I was trying to build tension. I think I built too much tension. Now I'm lost. Don't want to lose her as a friend I also don't want to go back to the brother sister thing. HELP!! PLEASE!! ANYONE!!