I too had the friend baling out issue,best friend since primary school,I got cancer December 2016,after telling her heard nothing for 5 weeks,not even a text, then a short text saying hope you well,that’s it. In 2 years since then 2 more texts,I was quite bitter for awhile,then about month ago we meet for lunch, things are different and will never be same between us but the lunch gave me a something like closure and I left it thinking we will happily go our own ways now.like you said there are many other who were there and stepped up,I just move on a invest my time with them.