Long distance lesbian relationship - slowly destroying me and need advice

I'm new here and need some serious advice.

I've been in a long distance relationship with a straight girl (or who thought she was straight) for over a year now and everything is falling apart.
It all started unexpectedly. I wasn't looking for a relationship at the time. We met online as friends and she was the one who initiated. I was really hesitant and not sure if it was a good idea. She seemed to absolutely want it and I gave in.
I didn't expect it to last. We had fights over her sexuality and my lack of trust in it. She's never had a relationship of any kind (before me) and I was very uneasy about that. She insisted over and over that what she felt for me was real. I was hoping she'd realize she's bi but instead she says I'm her exception.

We've shared pictures, talked on the phone, skyped. But from the beginning she wanted me to visit her. The problem is she's over a thousand miles away and I didn't feel ready.
It's a mix of reasons with one of them being that I was afraid meeting would change everything and destroy us. I was afraid of losing her and the powerful emotional connection we have.

I hesitated too long because I found out recently that she met a guy. It was a very surprising and unpleasant way of finding out, but she (and her friends) swear she hasn't cheated and she told me she planned to tell me once she figured out exactly what her feelings are for him. He admitted to having feelings for her. She said she cares for him but is in love with me, and that she would still choose me.

I ended things immediately and she was devastated. She tells me she doesn't want to live without me in her life, but at this point she's unwilling to give up this 'friendship' with the guy. I think she's really given up hope for us but at the same time doesn't want to let go of me. She says she'll always have some hope that there could be a future for us.
She's also begging me to visit her still and this is where I'm torn.
Should I do it? Should I take that risk and just find out what would happen? But then I wonder if I'm just an idiot to even hope.

I feel sick over this whole thing. I can hardly sleep or concentrate at work. I've cried...I've drank. She admitted that she could see herself falling for this guy and that he reminds her of me. I have nightmares about her with him. She claims that if I visited her she'd choose me, but until then she isn't giving him up. She even suggested an open relationship even though neither of us believe in them.

I don't know what to do. She still doesn't want to let go of me and I still love her.

 

That's exactly my fear. I guess I'm still in shock at this point because I really started believing in her, and us.
I think her feelings for me are genuine but I sense heartbreak in the future even though part of me wonders 'what if'. A few people have suggested I'll regret it if I don't go there and give it a try. But when I consider it I think of this guy she likes.

Thank you for your support.

I really have no desire for another long distance relationship. They're excruciating unless you can find a way to actually be together.

Our relationship is so complicated even apart from it being long distance....it's just so hard to give up on someone I actually love and believed in.

 

I was really starting to believe we could make it work. I was starting to trust that she really wanted to be with me even if I'm not her preferred gender. And then I found out about this guy...

I know she likes him. She claims this only happened because I won't visit her, and that it has nothing to do with gender. She says she needs me there or else she has to move on.
But she never mentioned spending time with this guy to me. I found out through one of her friends by accident. She made a choice to not mention when she'd go out with him, so she was hiding it from me.