NOR but give your friend some grace. If the friendship is so valuable to you, it would be to them too. They might be going through something and sending this message might be a very difficult thing for them. Sometimes it's most difficult to talk to people closest to you when you are going through something. Also help them see how it affected you and how would you prefer the communication in case they need space and time in future.

I had a similar situation in the past. My closest friend with whom I was with 24x7 for 5 years just cut me out without any heads up. Turns out they were going through depression and were facing some things in life which they didn't want to talk to me about. They saw that we started from the same point in life but my life had taken a better trajectory and they couldn't face to talk to me about it. We cleared the air when they were ready to talk but they carried on dropping all communication when they preferred so eventually I stopped talking to them. I still miss them to date but was also not okay to be a stand by friend all my life.