How to make my girlfriend happy?

long distance relationship...i see her once in a while.... well she upset with me for alot.. and i'm trying to make her happy with love words or being romantic... or sumthing...bc the way i act now doesnt seem to make her happy like i say i love you baby and she either says ily2 u2 or ik.... please help i feel like she wants to leave me bc she told me she felt like leaving me but she doesnt really want to...how do i fix it??? PLEASE HELP ME????