everything also she say... what about u? do u have feelings for
her? 
if u do, why do u even ask these questions...
if you don't, why are you with her in the 1st place...
Generally i guess feeling means u "feel" that u can grow to love a
person, that if you are with that person you can resolve any
problems, you feel secure when that person is around, anything is
possible with that person etc.
When a couple breaks up, it can be for various reasons... feelings
can die if not nurtured properly... how to nurture it is uniquely
dependent on the individual person... so people need attention all
day long, some need a private space, some overly protective, some
just dun show their affections openly etc... so u really need to
understand a person well to keep the feelings he/she has for u
alive and growing... 