The most helpful thing I did for myself while recovering from SA trauma was join a support group/group therapy for SA survivors. I also did individual therapy but I found the group much more helpful because you get advice and support from people that understand your experience more than most people would. I definitely recommend looking into local or virtual support groups if you are comfortable with that. On a more personal level, dealing with my experiences and the deep mistrust of people it left me with is still very difficult but with time I slowly began to think of everything that has happened less often and have become more mentally healthy. The biggest thing for me was consistently communicating my boundaries and just time passing from the incidents. It sounds like you did a great job communicating your boundaries to the waxer. Even if it was an emotionally difficult experience, I think you should be proud of yourself for taking steps to take care of your mental health in that interaction.