Button, while I can't comment on whether or you are gay (only you know that), I can tell you, with certainty, that your T's "theory" is a bunch of baloney. In fact, it's incredibly homophobic baloney. This falls into my personal area of research, which I teach at my University, and anyone in my field, at any University you go to, would be absolutely horrified to hear a T spouting this kind of stuff. Sadly, many Ts do not have sufficient training in sexuality studies and end up doing more harm than good with their LGBT clients.

Anyway, let's look at her "theory." In order for her theory to be true, we would have to assume that all women are "naturally" born heterosexual-- and then, if they are neglected by their mothers-- all or some of them "turn" gay-- and since heterosexuality is the assumed natural state-- then perhaps they can "turn" back. Of course, there are about 20 things wrong with that. First of all, heterosexuality is not "natural" or universal or the default. Her theory assumes that, if everything were to go "right" in parenting, then no one would be homosexual. Of course, that also is not true. And what about those women who were neglected by their mothers who turned out heterosexual? More to the point, her theory assumes that parenting is what "causes" homosexuality. By her theory, if a child comes out to her parents, then the parents would actually be correct in saying "oh my goodness, where did I go wrong?" But, of course, parenting does not "cause" homosexuality. Furthermore, if we are looking for a "cause" (and then, presumably, a "cure") we are taking the homophobic position that homosexuality is "bad" and should be eliminated, if possible. Of course, this is not the case, either. To assume that any one factor (i.e. parenting) is responsible for something as complex as sexual identity negelects the million other things that go into shaping our sexuality (both biological and social). Moreover, your T's theory is completely ahistorical. As we know, the idea that we HAVE a sexual identity is a modern construct which has only existed since the 1870s. Prior to the 1870s, sexuality was viewed as a behavior-- something we DO-- not something we ARE. The sex/gender of our partners was not a component of our identity; this idea changed as our culture changed. So, to say that either homosexuality or heterosexuality are "natural" could never be the case because these terms (and the ideas behind them) are something we created, socially, in the last 140 years. Prior to that, there was no stigmatized category "homosexuality" because our culture had not created it-- and, "heterosexuality" as the "natural" category we think it is-- did not exist as such until it rose up as the opposing term to homosexuality). Anyway, my point is that there is no way to view our sexuality outside of the culture in which we are enmeshed. And, because we now live in a homophobic culture, that homophobia shapes many of the ideas that people have about sexuality-- they try to come up with theories to prove their own worldview, no matter that most of these theories are innacurate. Finally, your is also doing something that is very, very common: she is minimizing, infantalizing, and de-sexualizing female desire. To assume that female sexual desire for another woman must REALLY be about craving "maternal closeness" is to discount the sexual nature of that desire. It gets onto the slippery slope of thinking that a woman's desire for another woman (i.e. without the man and his penis and "natural" heterosexuality) is really about closeness and if sex comes into the mix, then it's really just transference from an innate desire for maternal comfort (because of early neglect). Those kinds of ideas are straight from Freud's "Three Essays on Sexuality" which have since been debunked by women theorists and psychologists ten times over. (Freud sucked at theorizing about women and about what he called "sexual inversion!") Anyway, I apologize if I've gone on a bit of a tangent here but, as someone who teaches and researches this stuff, it really makes me angry when professionals who have NOT done any research spout off these half-baked theories without even recognizing that they are spewing homophobia. (Oh, and there HAVE been clinical studies on "does being neglected by your mom make you a lesbian and does being neglected by your dad make you a gay man; the research said NO!)