What should I dooo???

So one of my reallly close friends, him and I used to talk every night for hours on end wether it be FaceTiming or texting. We did this for about 1 year and 1/2 and then all of a sudden the next day he just stops talking to me and this has gone on for 9 months, like we will occasionally talk, but it’s nothing like it used to be. And I may sound selfish, but I really miss talking to him, because he always made me smile and laugh, and was just so amazing. Yes I had/have feelings for him, and he knows also, like it’s not a secret. And I thought we were actually to the point of almost dating, but then I don’t understand what happened. I asked him last night what happened, and he said nothing really “happened” we just grew apart, but like I don’t under how we can talk for that long and then the next day we all of a sudden grew apart?? Like I have no idea what to do, like do I ask him like again or something else, cause things are never going to be the same and I want to fix this before he dies. Also he has pancreatic and liver cancer, he still goes to school, but it’s getting worse, and I want to make things right between us. He said he still has a while left, but not sure how long.