Is it normal i fantasise about only girls yet fall in love with only boys?

I used to fantasize about guys when I was a teenager (since then nothing). Now I can only get off when thinking about other women. I have quite a lot of insecurities about my body and find it hard to get close to people and be intimate. It bothers me because when I'm having sex with a man I sometimes can't get turned on. I feel lesbian fantasies may help me be sexual in a safe environment/ comfort zone (as Im comfortable with my body about girls).
When it comes to crushes, love, minor infatuations (ahem) it has always and will always be men. Yet by myself i cannot get off to the thought of guys or straight sex.
However I have no emotional or sexual attraction to women in person. To me they are the object of body/ clothes envy when I'm checking them out. I associate women with empathy, friendship and sisterliness.
I am nervous about guys, will always check guys out in the street or in bars and have fallen in love/ fancied them. Yet can't properly get turned on by them! So annoying!
p.s. sorry for the long poll