I'll tell you what man I have been in individual therapy for just under two years and will be attending my first group therapy session here in a week. From what I have read and been told about group therapy it is an excellent resource but only if the survivor is ready for it. Otherwise, he/she may not get the most out of it and will possibly come to the mistaken conclusion that it is ineffective. Apparently, what your therapist said about strong emotions is true. Some groups caution against a survivor joining up until he/she has been in individual therapy for a certain amount of time. Nevertheless, I am not speaking from experience at least not yet. For now, especially if you trust and are comfortable with your therapist, I would suggest deferring to them.
"Life is like this dark tunnel. You may not always see the light at the end of the tunnel, but if you keep moving, you will come to a better place." ~ General Iroh