Hi bpintern, welcome
I don't know what EMDR is, just looked it up it's Eye Movement Desensitization and Reprocessing. This site PC seems to recommend it for ptsd and trauma. I read on some other sites it is recommended for bipolar. Sounds good, makes sense I think because we are more sensitive to light, sounds, people, everything. Any healing and coping skill is helpful. I think it's good but sometimes hurts to process feelings, if we don't they get stuffed and have to be dealt with eventually.
If it's too much for you, I would hope your therapist would know how to guide you. Maybe it's best to power through it, or not. Maybe a rest is needed. Hopefully some people here have experience with it. But good for you for facing this stuff and looking for healing.