Hi John.
Please ignore well-meaning but ignorant advice. There's nothing wrong with you other than that you're human. First, about fantasies: as you might expect, the most powerful ones are those that are the most forbidden. For example, it's not unusual for a life-long Lesbian to fantasize sex with a man, since that's the most forbidden activity for her. It doesn't mean she wants to do it in real life--it's merely the most exciting in fantasy because it's forbidden. Because it's forbidden for you to think about men, guess what? That's a big turn-on. The more you worry about it, the more powerful it will become. You probably will never want to act on it, but if you do, so what? It's part of who you are.
And please don't worry about so-called "porn addiction." There is no such thing. It's perfectly fine to fantasize and look at imagery that turns you on.
The reason you're confused about orientation is because society itself is confused. We try to put everyone in a box labeled gay, straight or bisexual, when, in fact, there's no such thing.
You are who you are. Some of us are born with a strong sexual orientation to one sex or the other, while others of us are more flexible. The problem comes with trying to fit into one of these boxes. We feel we have to define ourselves; and yet, once we do, many of us feel incomplete and confused. That's because sexuality is fluid and indefinable. Many people have sexual experiences with both sexes throughout their lives, as well as falling in love with both sexes. And many people only fall in love with one sex, but are sexually oriented towards both. And vice versa. Life is SOOO complex!
And just to complicate things further, we can change many times over the course of a lifetime. You may be into women for your whole life, then men, then women, etc. We can never know what’s around the next corner. Tomorrow you might be walking down the street and fall madly in love with a hippopotamus in a tutu!
So the short answer is: resist putting yourself in a box and being defined by others. The longer you can do this, the more you can get to know yourself outside of these artificial categories and take charge of your sexuality and relationships. And if anyone tries to force you into a box, why not just say: “I’m sexual.” Period. Best of luck to you. Dr. J
Hey John
Please don't be offended by my opinion, but I believe that you need to seek professional help. I am not a Doctor so I will not even attempt to analyze your problem but simply from reading your post its clear you could do with qualified help.