Cptsd is the complex variant resulting from child abuse, followed by trauma in adult life, and needs specialist handling. It is not about letting out tears (although I can understand that feeling), but far more complex.
It is about establishing safety, remembering, mourning and, eventually, reconnecting, according to Judith Herman. I would recommend her book Trauma and Recovery, followed by therapy with a trauma specialist. If that specialist uses hypnotherapy then fine, but I do not personally think that a non specialist should attempt treating anyone with cptsd. I have this condition myself, and have lost count of the well meaning non specialists who have retraumatised me over and over again. I would not submit to hypnotherapy myself for the simple reason that I am highly suggestible. If anyone in authority tells me to do something I find it a real struggle not to comply. That is bad enough, even without the hypnotic trance.
Dissociation plays a huge role in protecting, coping with and living with cptsd, and hypnosis may well interfere with that, because the trance states are likely to be very similar.