Bisexual or HOCD?

I'm confused as to whether I'm bisexual or I have HOCD.

I'm a girl and I've liked a lot of guys in my life. I've been in love with an amazing guy, I've cried over guys, I've loved guys, crushed on male actors, enjoyed straight erotica/porn, had enjoyable intimate experiences with some guys, had two boyfriends - one turned out to be gay, the other was great for a while, but then he turned into a bit of a jerk. Granted, I do have a soft-spot for feminine guys, but if you're a hot guy, chances are, I'll be attracted to you.

When I was 15, there was this girl at my school who I slowly developed feelings for. When I met her I felt excited, and whenever I saw her I wanted to be near her, more than any of my friends. I thought she was amazing and I (this is a cliche) would listen to music and think about her. We had to practice partner dancing in sports class and I danced with her and I felt all nervous and I blushed so much around her. I'm not sure whether this is just a normal, straight 'girl crush' because I could never work out it was sexual or just romantic or what. I felt sad when she left my school as well.

But ever since this happened, I then started to notice more girls. I would start to check girls out, but then think "this is wrong". I would also get crushes on female acquaintances, teachers, some female celebrities etc. I found myself blushing and getting nervous around certain girls and doing stupid things like opening doors for them or rambling on about something silly to impress them. The only thing is, I would check guys out too and I would do the same things around hot guys. I still am physically/emotionally attracted to guys and I lust after guys and have the occasional hookup or date with a guy - I don't have a boyfriend now though.

Anyway, I started watching The L Word and found myself identifying with Jenny's character in the first season, but then she turned out to be lesbian and I couldn't identify with that. After that I felt like Tina or Molly was more like me. Anyway, after the L Word finished, I became obsessed with lesbian-themed things and began to secretly indulge myself in this. But I love gay-man themed things too like Queer as Folk.

THEN, I met this friend of a friend and my feelings for her came on so gradually I don't know when I fell for her. But now I really really like her and I can't stop thinking about her. She gives off this masculine energy and I get gay vibes from her because of how shy she is around girls and how comfortable she is around guys and she has this "best-friend" of hers that she treats like a girlfriend and she's always making suggestive comments about lesbianism. After I see her I always feel frustrated, I feel like I'm going insane and I get really moody. Because I'll be thinking about her, then the next minute a hot guy will come up to me and I'll be totally attracted to him and I'll think, "oh I must be straight but I like her..."

So I don't know whether I have HOCD or I'm actually bisexual...

In terms of finding women physically attractive, I am sexually attracted to certain women, including this girl, and I do enjoy looking at naked women and watching lesbian porn as well as straight porn but I find guys are more sexually intense creatures. I also have never hooked up with a girl and I don't know if I should. It does interest me, but I'm worried I'll open a can of worms. And I do feel a sense of shame about my attraction to my "friend" and I get butterflies or a "sick" feeling in my stomach when I think of telling my family about her. I tried to tell my parents but I just lied and said this girl made me "uncomfortable" and she was "manipulating me" or something. Then my dad was like, "I thought you were going to say you were gay," and then I explained, "No! I like boys!" which isn't a lie, but it's not the whole truth.

So - am I bi? Does bisexuality really exist as a complete identity or is it always "a phase"? I'm now 19. Because I'm so worried about being bisexual because I'm scared it doesn't exist.