Literally did this about two months ago and it was the best thing I've ever done! Fortunatly for me, I didn't take it as far as you haha, it was more like 150 I unfollowed.
I went about it a little different thought. I went through each of the pages I was following and determined if I liked their content and un followed accordingly. Once I did this, my home page was filled with content that I actually wanted to read and it made my Steemit experience so much better.
Within days I was able to make a friend who still supports every one of my posts! I slowly started increasing my network and now my whole experience feels so much more authentic! I'm literally about to make a similar post about this today, so I had to stop and read what you had to say. I think you made a great decision! Just start finding authors you like, and make sure you comment on every post and pay it forward, and you will be Rep 60+ in no time! Great article utfull!