Regardless of what you imagine your relationships status to be in the next few months, it's important you take care of yourself first. You said before that you don't know quite what to do with yourself (when she's not around and you are imagining her with other people). In a similar situation, I would find a past-time I don't necessarily have to share with her. The more time-consuming, the better. Excellent hobbies are those where you really need to concentrate on the what you are doing atm and not on what you're doing in general with your life. Be it mountain climbing or 3D-card-making, think of something to do at those moments when you feel at your loneliest.
I'm no expert but I have a gut feeling that there are many more people with same-sex experiences at some point of their lives than there are people who self-identify as bi or gay. So you can practice homosexuality (or bisexuality, or whatever), without necessarily identifying as a lesbigay. On the other hand, someone with no sexual experience at all can still identify as gay, straight, bi, a or pansexual. I have even known young lesbian-identified women who have only experienced romantic and sexual relationships with men.
So you can practice polyamory without being poly, or poly-for-life, or exclusively poly, just like most poly people have some experience of monogamy. My point: you don't need to know yet if you are poly. Hell, you might never know. So you feel right now you might be mono and don't know if it's something that will change at some point? That's fine!
I hope this cleared up at least a bit of what I was saying. I always get feedback for my super-curt writing style at school, and it tends to backfire in other contexts, too