I miss my cousin so much :( ?

while writing this i could feel tears in my eyes, im 15 and me cousins 22 we grew up together,honestly ive been close to her since i was like 2 ? i went everywhere with her did everything together but now obviously we have to grow up someday and now she has a son which is 2 and her boyfriend the babys father and my cousin just split up like a 1.5 year ago now she has a new boyfriend which i honestly really like but i REALLY miss her :( i get to see her like twice a week or sometimes once but always on the weekends she works where me mum does so theyre really close. Tomorrow shes going on holiday with her boyfriend and the baby and about an hour ago they just left the house she kissed my cheek and said see you in 2 weeks i was like 'mwah see you :)' but when they went i just ran to my room and cried. I mean i miss her,when i was little she was my rolemodel she told me EVERYTHING. how do i stop this ? like i said i know we have to grow up and she'll make her family and i go my own way with school and stuff but :'( help ?