I think it's helpful to first understand how EMDR came about. Francine Shapiro was walking through a park thinking, as usual, about her problems and she noticed that by the end of her walk she felt so much better. She then realised that as she walked through the park that she was glancing from one tree on one side of the path to another on the other side, creating rapid eye movement (similar to when we dream at night) which led to her creation of EMDR to process those painful memories that have been pushed aside at the time because they were too painful to deal with.
The reason it is so successful for trauma is due to the act of rationalising your thoughts whilst simultaneously experiencing your feelings. The same can be achieved with hypnosis whilst receiving rational questioning or, if the patient feels safe with their therapist, they can let themselves ‘go there' using pure CBT. However, it's often difficult to access those abject moments or terror or sadness in a clinical safe setting. The EMDR also confuses that state, a little like rapid hypnotic inductions (which are rarely used in the therapy room, more for the stage).
The source of the negative emotions is only relevant in terms of how you feel now, your perception about how it's affected you along with any regret, guilt, loss, grief etc. It's about accepting that the past can't be changed and processing your situation in the here and now, looking forward and then being able to look back whilst only experiencing the memory without emotion, as the pain is gone.
Another great analogy is sitting on a train with all your baggage and as it comes to each stop you drop one of the bags off and you feel lighter and lighter as you move along the tracks (each EMDR set). It can be a very liberating therapy.
During the reflection after each EMDR set, the questions are CBT based, so rational and based on the thoughts that were behind the feelings, so the two work well together and some of the less painful questions can be talked about in more detail outside of the EMDR process.
Hormonal anxiety will up your stress hormones and add to any negative thoughts as this is not thought driven, it's your brain assuming there's a problem due to sudden hormone crashes and pumping out extra stress hormones to allow you to run from the perceived problems. The physical sensation is the same but the source is different.
The main thing for you to remember in EMDR therapy is to stay in the moment, just let out whatever thoughts you're having (some may seem strange and unrelated but they can be behind what you assumed was the cause). It's about how you feel now, not how you felt then, as this is what you're living and experiencing right now.
Your therapist may next try pure CBT with you so you have a direct comparison as to which is suiting you better. They should then remain flexible to you choosing one over another.
Most failures in EMDR and hypnosis are down to the patient not understanding what they're meant to be doing. Neither are passive so strong instructions are key, particularly in hypnosis where it's all about intent focus and nudging away the conscious thoughts that pop into your mind every now and again.