Not So Innocent Crush

It all started in high school, now I think back on it, it was the beginning of the end for me, and quite possibly for him too.
Now I have a girlfriend whom I adore, but meeting him again has awoken feelings inside of me that I had forgotten about.
Now I feel as if my life is an old building that is crumbling around me, I am hanging on for dear life using the thinnest of strings, rope burn threatens me, mocking me with all I have and all I could have had, I am not a strong person, I gave into peer pressure all my life without a second thought, but now, now that its quite literally do or die.........
I have no idea what I should do, who should I choose?
Should I choose the one that could have been?
Should I choose the one that is always there for me, through thick and thin?

Can I choose before it gets way out of hand?
Will it be too late by the time that I make a choice?
Will I end up losing it all?
Could I maybe have it all?

Am I doomed? doomed to fail.