I think I have read enough to understand what you are going through,Varun.Heck,it has happened to me too
(except the fighting part).You see I also had a huge crush on this one girl for the last 6-7 years or so.I changed my school so couldn't act on those feelings.
To be honest,I feel now,that it was just an attraction.The feelings took a little time to vanish,but I can say this to you that,I didn't love her.Infact,at your age(we are of same age),there is a very little possibility of you actually falling in love.It most likely is just mutual attraction.
But,from what you state and if you do actually love her,then your "friends" or these external factors shouldn't affect you one bit.What matters is that it is a 2 way street.Your girlfriend is an emotional person and she is disturbed by these fights but you ought to explain to her privately that it is actually her who matters.She should act on the relationship if
she feels like it,not what the others (read your other 2 friends) think!
But proceed these emotional provinces with caution,you have said(and truly) so that you could move on,but could she?She has tried to take her own life once and chances are,she just might do it again.To entirely convince her,are
you convinced you are ready for such a big commitment?
On the parents' front,do not tell them.I know Indian parents and it might make things worse.If you do think of telling them,Just absolutely dont tell them before the boards.
Last,your life is more important than anybody's.Take care and best of luck.