Yes, this is how the cycles of PTSD happen. Most people experience this in their lives, we all ruminate and reflect back on our history, we do that because as we live our lives we continue to learn and grow and understand and learn more and more from different perspectives as we get older. It is just greatly "magnified" when someone struggles with PTSD. That being said, it is not unusual for a person to develop PTSD "years" after they have experienced trauma/traumas of some kind. That was recognized when a commemorative ceremony was offered for veterans where they got together, watched video footage and a discussion of the war they took part in and were honored. Many of these men had gone for years living normal lives but now began to experience PTSD and were very confused.

I have never had EMDR myself, however, what I think really happens is that when a person goes through that process, they don't face "dismissiveness and disbelief", but instead are allowed to express their traumatic events and feel "believed and heard" and that together with the eye movement is most likely what is behind gaining a sense of "relief". That is just my opinion however, what I feel is significant to presenting a sense of "relief" is having another human being "believe the trauma without question".

I am so sorry you are struggling right now, I know how challenging that is Teacake. However, IMHO, the relief takes place when you are able to talk through it and gain validation, which is something you have not had. And I have gone into that in more depth in your other thread.