Bring the entire sequence back to your therapist:
I told you X
I went to my mum and she “corrected or explained” my version.
Now I am more confused, feel guilty, and am worried about how you (therapist) think about me (patient.)
Let your therapist do her job! Let her help you!
Its a symptom of how difficult your childhood was that you are experiencing nearly continual overwhelm and anxiety over the relationship with your therapist. You imagine/anticipate/fear that she will “retire” or “win the lottery” or “think you lied” all of which are fantasies of rejection, abandonment, and which would naturally put an end to the therapeutic relationship.
I have sat in her chair, as I am a therapist, your concerns are natural parts of the therapy process. The closer you get to her the more anxious you become, for a while, that she will leave or reject you as “imperfect” or “a liar” or whatever else judgmental and cruel things were said and done to you as a child.
She won’t reject you or fault you for having said one thing in therapy about your family and then denied it. Dysfunctional, toxic, abusive, or just very fake families often produce children with imperfect memories, or who feel impelled to protect the family by “correcting” the record. In reality patients tell the truth in one session and then abase themselves and say they “misremembered “ or “misunderstood” in the next because they fear the cruel repercussions of family members for having exposed the family’s secrets and abuse to outsiders.
This black and white thinking—-that you have either told the exact photographic truth or you have lied is not useful. Whatever you told your therapist was your experience as you remembered it. The fact that your mother claims to have a different interpretation or more context is not a sign that you “lied.” Its just more context.
At any rate your therapist will havd seen it all before. Stay in the therapy. Work somatically to calm yourself between sessions. Swim, dance, meditate, take up pottery, yoga, walk…whatever feels good.