Confused

So I've liked boys since I knew what liking boys meant. I started my second year of high school in September and started liking this girl around October when I found out she likes girls. I don't have a crush on any other girl but her and I don't know how to go about it. I've never felt so strongly about a female before. I think I should add the fact that I'm also talking to this guy which has me in a really tight spot here.