So on one level, polyamory has a natural appeal to you, but at the same time, your girlfriend is the person who your heart is rather set on. Maybe you need some more exclusive time with her before venturing too deep into the poly waters? You can always support and appreciate the "other end of the pool" regardless of what's working for you at this moment.
Keep us posted and don't hesitate to toss any questions our way.
Love means never having to say, "Put down that meat cleaver!"