Is it normal to have uncontrollable thoughts and dreams of a girl...

I seem to have a lot of uncontrollable thoughts and dreams about girls, but mostly one girl in particular. I have a boyfriend and I've never experienced being with a girl. Ever since I was young I've always been attracted to girls, when I was in middle school my best friend would lean close to me or lay her head on my shoulder and I'd get extremely nervous and blush really badly. My friends that are girls often wonder why I stiff up and barely hug back when they hug me, Idk how to explain it. I also have social anxiety so I have a hard time expressing how I feel to people unless I'm really really close with them, like I am with my boyfriend. I have a friend who's bisexual and who has shown interest in me. I guess lately I can't stop thinking about it. I've had thoughts of us taking a shower together and making out. Ugh I feel like I'm going through puberty all over again, I kind of hate this feeling, but my thoughts won't stop. :/