Hey, I'm in my mid-30s too and have done this a few times throughout my life (dropped most of my friends). I always used to worry that there was something wrong with me, like I was turning anti-social. I finally figured out that I have a bad pattern of developing really unhealthy friendships and keeping them until I just burn out.

So it could be a good sign that you are dropping your friends. I really like your security blanket analogy. Everything is going to be okay

I found it helpful to sort of examine why I wanted to drop these people so I could avoid making friends like that in the future.