I know that no amount of "sorry" could ever help, but I am awfully sorry it turned out that way. I can truthfully say that I've been in the same boat; a friend of mine passed away two years ago from brain cancer. I have no doubt that your friend was a true warrior. Prayers for you and yours. <3
Sorry for your loss. It's a shame to lose a friend, i've lost my grandma that practically took care of me while my mum and dad were somewhere else for my entire life 2 years ago. I also lost a classmate of mine when i was 10.