Im saddened to hear that sis . I will remember you in my prayers InshaAllah. May Allah swt make this time for you and your family easier and grant you all many blessings .
Sis , as everyone has mentioned - it is good to spend this tme in prayer, repentance, reading qu'ran and performing good deeds as well as spending time with family and friends.
Now im not sure if this is allowed in islam - may the other brothers and sisters correct me if im wrong - but how about recording something like a video diary (do it in private) saying nice and beautiful things about your individual family members and friends. Either way many ppl can benefit from this - if (Allah swt forbid) your time has come - your family and friends will draw strength and comfort from this recording but also if you do get better or live longer than what doctors say InshaAllah - you can look at it yourself as a reminder how temporary this life and dunya is and gain and strengthen your iman with this.
But remember also sis all you can do is be prepared InshAllah Allah swt only knows when your time is up - make the most of this "warning" period and live and love for the sake of Allah.
I hope i havent sounded insensitive and may you forgive me if i have.
I love you for the sake of Allah sis. And dont hesitate to contact us and just talk about how your feeling or whenever you need extra support.