Having a good childhood is a blessing and gives you a good foundation. Sometimes horrible things happen, but it sounds like your headed in the right direction and healing. Sometimes we simply can't see it or it's subtle before gradually increasing or we feel something is off in our gut, yet we can't fit the pieces of the puzzle together.
There are numerous times I've had immediate relief and results from EMDR. There are also times where I've ran up against some road blocks and quite a bit of disassociation. Due to trauma (not sure if it was intentional or not) by a previous t doing questionable emdr and I swore I would never ever go to a therapist again.
This all happened following a long period of intense ongoing trauma and complete disassociation in more than one areas of my life at the same time. I was essentially triggered into a state emotionally, that I can hardly even describe. It still terrifies me to think about it. That was over 5 years ago.
I don't know how it happened, but I got referred and miraculously I tried again and I've been with my current EMDR t for two. She's a perfect fit for me, but it has been incredibly challenging. What amazes me is seeing changes in myself I haven't even tried to make happen. I never dreamed I would make the progress I have but then other times the pain and emotion feels so intense and I don't feel like I'm ever going to make it.
She's so in tune with me it scares me to death, yet it's a relief to feel like someone truly gets me. We've had to take a break from EMDR, because Ive hit a block and disassociate even when we do talk therapy. It is such a struggle to work and deal with everything else in life and do this at the same time.
I'm so glad your son is feeling positive with EMDR and is having the opportunity to receive help. Truly, I think half the battle with teenage and young adults is sometimes recognizing that it can help so much and EMDR can provide immediate relief for many people as well as privacy for those who don't want to or can't verbalized their trauma in detail.
I kind of posted a lot...:)