Hey Sterella,
I know exactly what you're talking about. I am a lesbian and I have felt what you're feeling when I first discovered who I was years ago. I didn't have it personally but I believe there is a denial phase as we discover who we are, hence the guilty feelings...
I honestly believe that sexuality is fluid and on a spectrum, not necessarily black and white. I can't tell you if you're a lesbian, only you can do that...however, if you've never been attracted to men and you find yourself attracted to women (even in dreams) that could be an indicator. It's definitely a confusing time, and I can relate to that.
I also had crushes on my girl friends when I was young. However if you have an attraction to no one at all maybe you're just asexual (not attracted sexually to anyone!). That could be something as well. I think it just takes time to really find your niche in who you are sexually...it definitely takes time. Go easy on yourself, you're not doing anything wrong.
I hope you can find some insight into yourself soon. Best wishes.