There's only one person I have developed an emotional attachment to and we can't be together because she lives so far away, because of this... I really don't know if I can ever become attached to someone ever again. I'm in so much love with her, we're both almost identical in personality and nobody has ever treated me so well in my life before. It's not fair, I need her by my side.
I don't know if you want to hear this but time does heal a lot of wounds, especially these romance ones.
Know and understand that there are many other girls out there.
You only have two options, either try to be together (only you know how realistic this option is, how old you guys are, if you can move out, if she feels the same way back etc etc) but it sounds like you have already worked out that it is probably best if you weren't together. The only other option is to move on. This will allow you to be happy and open, but are you ready to let go of the past?
Holding onto something that is not there is a waste of time, -everyone says that in retrospect. Don't become someone who says it!