What can i do i still love my ex?

i am 15....and she is 17 i really dont care how old she is. i have cancer and she is the olny one in my life now whos olny my friend that really cares about me my mom died and my dad beats me sometimes she the olny one i want be with, but she boke up with me bec she could not deal with the cancer but i dont under stand why bec now she wants something from me a baby i dont kno why and dont kno if she just saying this i am 15 just turn it but act like 18 i really do love this girl what can i really do to get her back i would do anything for her its just like this i did dateing her for like a year sicnce i was 14 to 15 when i was 14 and half i got cacner and aslo i was bbf with her sicnce 3 garde i think why she wants a baby from me is bec she freak out and sared olny one thing she wants from me is a baby she almost 18 teen she tell me she can hanlder this but i dont really kno bec i am dieing and i dont want her to have it and if i die i cant help and we are not even bf and gf