Im going to apologize up front, because im going to be an vulgar asshole and say what your parents, her parents and your friends should have said to you. I am in no way looking down on your actions, they were quite honorable.
WHAT THE FUCK IS WRONG WITH YOU! the very fucking moment you realized that you loved this girl, you should have contacted the school and taken a minimum of a 6 month leave of absence and spent every fucking moment with this girl. goddamned dumb motherfuc...
once you realized how you felt about her, what she meant to you, you should have fucking begged this girl, on hands and fucking knees, to marry to you. you knew she had very little time. school could have waited, it would still be there in 6 fucking months. you should have given her everything you had. all of your attention, all of your time, all of your support, every goddamned ounce of strength you had.
*sigh*
I know this is all in hindsight, but these are things that should have gone through your thoughts and the thoughts of the people around you. all this being said, you did a very good thing. you gave her something she very much needed, a great happiness in time of immense sadness.