Boy can I relate. When I first started to recall things, I really didn't fully trust my own memmories either. Thank God my therapist was supportive through my self-doubt. Or else I'd be dead right now. I felt so unsure. I didn't want to believe myself.
I think you have to go with your instincts. And if your therapist seems unreasonable, change. This is terriblly hard as it is to deal with, You NEED a support.
They will not Give you peace, you must find it yourself, you have the power within you, but you are not alone, We will find it together. -Blacken