This is all so hard,can anyone help me understand?

my bf was diagnosed with cancer 1month ago,im devestated,we use to live toghether before his diagnose,he is living with his parents,because they became upset with me because i told him they need to help me with his 5yr old daughter while he was in the hospital,he told me prior that his family treats him,his daughter like black sheep of the family,and doesnt want to be supportive towards them.so the family became upset and had him move in with them after he was realesed from the hospital.i think he needed to be with his family so they can take care of him in his last days.(i heard the mother resents him being there)anyways i cant visit him or call him while hes there,he calls me once aweek,and i write him letters weekly,i have asked him are we still gf&bf?he just says (sadly)i need to think about everything.he tells me that he loves me and is in love with me.he is currently taking high doses of cancer medication,goes to chemo&radiation treatments weekly,he had a seizure last week,he called me and let me know,i dont want to lose him,and this is so hard,i wish i knew what to do?ive never been threw something like this before.can anyone help me?