First, thank you for the mention - I'm thoroughly glad that you enjoyed watching "Giant Little Ones"!
I also loved reading your article about the film and how your life has affected your viewing. While I try to quickly reflect over the memories of my youth, I can't recall a truly good friendship that was destroyed when I came out. Sure, plenty of people I thought supported me and were friends turned out to be the friend of the "straight" me - such as the church, youth groups, some of my Scout peers, et al.
But this comment of yours really stood out. I think everyone has lost someone in this manner, perhaps not always because they were queer (as in my case). But it's crucial to realise that we need to mourn the loss. It's not always a realisation of your true friends, as I've often told myself and others (and even you remark upon). But I think Giant Little Ones shows us that even after suffering through such a loss, there's still hope and a better life afterwards. Which is an important story to be told.