I hear you. My first love has changed my life--that silly nonsense from the media about love causing people to walk on air in absurd ecstasy was no longer nonsense! It's so different to feel complete, to be one with a stranger after talking to them just a few times, and feeling like you belong somewhere--in that person's arms. I've also heard that first loves never really do end, and I believe it. As for "ending" due to loss of life, I have a few things to say. Due to moving far away, I've had to live without the people who sustained me, and had found myself alone. I think the greatest therapeutic, when you have something to say to someone but can't talk to them, is to say it without them there. Write an e-mail or a letter without sending it to anyone, or pick up a telephone without connecting to a dial-tone, and just talk as if your girlfriend were there and listening...she would want to hear what you have to say. If you can, if you trust someone enough for this, or if you can see a counselor, therapist, or psychiatrist, pretend that that person is your girlfriend, close your eyes, and tell them everything that you would want your girlfriend to hear. This is extremely effective--it can heal, but you should approach these methods only when you are ready. After I lost my significant other, I would continue to talk to them, in my mind, and imagine that I was them responding. I was sure I was crazy, but it was a relief, to live our relationship again. Well, after looking online for comfort (just as you did!) I found an interesting article at link removed about grieving, and what is acceptable in it and what isn't. There is also a discussion on people who have lost their partners at an early age at link removed
Check out the links on the left for some enlightening questions for people who have lost their partner. I wish you all the healing you need. Move slowly as you do this. It will be better for you in the end.