I understand what you say, but it is much more useful to focus and work on things that you can remember than ruminate over stuff you can't. For instance, why don't you focus on emotional neglect. Also, the fact that a child would almost end up in an orphanage because the mother cannot handle the child's panic attack should already give plenty of important material to work with. Why don't you work with that? Neglect such as this is already enough to produce a trauma and this is what your trauma therapist could focus on. You have better chances to find about your sexual issues when you start exploring things that you remember about rather than obsessing about potential sexual trauma that potentially never happened.