Struggling with Intimacy After Childhood Trauma

I had been seeing a single mom of two girls (14 & 5), and the girls at least used to be really becoming attached to me, because of how good I was with them, plus how happy I was making their mom. But in the last month or so, their mom & I have been having a lot of arguments, mostly because I struggle with my esteem, and being able to express/experience a lot of intimacy (especially physically), after I was molested by a neighbor (not "next door" exactly, but on the same block) at 10 y/o, and I was honest with her about my issues from the beginning, and she said she was understanding and willing to be understanding/patient with me if I was ever triggered by something, but as soon as I started to, she started to become more and more "frustrated" (she claims she was never/was not 'angry' with me), saying how much she hated when I started shutting down and being 'upset', because she says she hates seeing me so upset, when I deserve to be happy, especially with how much the girls 'love' me. The problem is because she gets so upset with me being so upset that she starts to yell/holler at me (again, "not anger, but frustration/irrigation/aggravation"), that she claims that the girls are being too hurt by our 'fighting' that she says she needs to break up with me, to protect them from being hurt anymore more than they already are. I just don't know what to do, because I definitely don't want the girls being hurt anymore than she does. I mean, I have an appointment to talk to a therapist starting tomorrow (first visit), but I am just so scared that any help I do manage to get will be "too little, too late."