You are so hard on yourself Lela. Can I tell you honestly what I think fwiw (which probably isn't much, as obviously I'm a microbiologist who knows bugger all about psychology really). I know that the trauma you're feeling is about having a boy. But I wonder really whether if you addressed your childhood issues with your mother/father then maybe it might give you some insight into the boy/girl baby thing and might help you work through what you feel and why you feel that way, and whether after understanding it all - facing it emotionally, not just intellectually knowing it - that some of your feelings about a boy might dissapate?
Sounds from your pp (and I hope I'm remembering this right) like your Mum (and Dad) were abusive/unloving and didn't treat any of you, least not the boys in your family, very well at all. Obviously your parents had major issues themselves. But none of that was your fault, or your brothers faults. And I know you undoubtedly KNOW but do you feel this? Its not because they were boys that your mother treated them that way - or maybe it was because they were boys? Who knows? But all that means is that she was a messed up individual and the reaction was down to her problems. You aren't your mother. Think of all the ways that you are different - I don't know you and I don't know her, but I bet you are very, very different. You come across here as someone so very upset about the welfare of her child (boy, girl or whatever), I feel you would protect that baby to the ends of the Earth - the most devastating thing to you is to cause it pain or suffering, be that with drugs or emotionally. Its crucifying you feeling like you do about a boy...because you're a loving, caring individual.
I think also the relationship with your mother (and father) may have fostered in you a feeling of being unloveable, unworthy of being acceptable, that your thoughts and feelings are bad or wrong. Many times the things you write you preface by saying that you're just such a terrible person for even thinking these thoughts - but they aren't that bad, they don't make us think you're a bad person - and we tell you that. But I bet you think...its just cos they don't know me, and don't know what I'm really thinking. And maybe that's true...cos we don't. But maybe its because you won't let yourself believe that you aren't bad or wrong or unworthy or unloveable.
You say that you've always wanted a child and your last depression was due to a fear of infertility. But now you find yourself pregnant and with a boy and you want a girl. But maybe you're so fearful of having a baby, and a baby boy at that, and that baby having the childhood you had, and its so overwhelming scary that you're almost mentally rejecting the idea or running away from it before there's a chance that anything bad has happened.
Give yourself a chance to breathe. Anything that helps...even if for 5min - do it, and keep at it.
I was reading The Times Sally Brampton advice page (now you know where I get my amateur pop psych from!)...and this struck me...
You can't 'think' your way out of depression because we get so trapped in our own heads that our thoughts become circular. We need somebody to lead us to a path that takes us out of the dark woods. You fear therapy won't work (in your case Lela you don't feel it is working/can't work). Well, therapy only works if we work with it. Its not magic. What therapy can do, though, is help us confront the underlying psychological issues that drive our behaviour.
Sorry for the essay and many apologies if I'm just way off mark. I really, really hope I don't upset you with any of this - I know you're feeling so fragile and low at the moment. I guess I just think you should keep on with the counselling - coming to terms with it, or addressing the underlying roots so you can move past it and be set free.
And one last thing...I know you say you have a plan if you still feel this way after the birth...and I know I always feel better having a plan. But your plan is not a good solution for you, for your partner, for your child or your family or friends. If you still feel like this after the birth - mother and baby unit. That's a good worse case scenario plan. [Or give them a ring now and see what they say - be completely honest with them about what you're feeling - rant, rave, cry - if that's how you feel.] But best case scenario....you'll feel completely differently after your baby is here and is in your arms.