I have the same thing happen, depending on what trauma I delve into and which emotions I get in touch with....
I am an EMDR therapist and would like to clear up a few misperceptions. EMDR was actually first designed to work with Vietnam vets who suffers with PTSD. The success rate in reducing symptoms was about 80%.
Since then, many protocols have been developed for various issues.
I use EMDR daily with most of my clients and am a consultant for other EMDR therapists.
Here is what I know. You can use EMDR safely every 3 days- and if you drink heavily or do recreational drugs you must be sober and clean for several days before.
If you are working on intense issues you will feel tired afterward. The first time I had it done on me I was exhausted but then my body adjusted and I have never experienced that again. However, I do a lot of trauma work and that can be exhausting and emotional every time for awhile.
When looking for an EMDR therapist please ask the following:
How much trauma work do you do
Do you work with PTSD
How often do you use EMDR
How long have you been using this method
Some therapists do not use it enough and are not proficient or don't understand PTSD. Your therapist should know your history and trigger points before using EMDR and should never let you leave in a high anxiety state, I have only had 3 people have bad reactions In 10 years of daily use and 2 of those had used drugs the day before and lied about it. If you do have a bad reaction, call your therapist immediately!!! They should get you right in to repair whatever happened. And I do believe that in trauma work, positive encoding and strengthening sessions must come first before ever hitting the trauma- especially with PTSD. There are a few exceptions to this-but should be evaluated by the therapist.
I hope this information helps clear up some issues.