Hi Chocoholic :)
I'm sorry I can't post a proper reply (I'm only up at this ungodly hour to do some work that has to be done for Monday, and I shouldn't be procrastinating by scouring MN in the first place), but I couldn't not answer your post.
I have this condition, and have posted on her about it a few times before (if you search my name you'll find a few threads where I and others have shared our experiences).
I'm sorry that you're having to worry about this during such a happy time (congrats on the pregnancy!) - I have only one dd but hope to have another dc at some point and I worry about how I'll cope with going through it again, too.
The feelings of guilt and failure were awful for me, but made much worse by the feeling of not being believed (even by LC's and HCPs who should have known better).
I wish I had advice for you, but I don't know myself what I would do differently next time around, except to give it my best shot (again) and then try to be much more focused on ensuring that my baby was fed and thriving, rather than obsessing over the source of the milk. If I had done that the first time around, dd would not have had to be hospitalised with severe dehydration in her second week of life 
.
On a positive note, other posters on this topic have reported that their supply has improved a little bit with each successive baby. From what I've read (and it's very limited as it's so hard to find anything about it) THB is characterised by a lack of mature breast tissue, which doesn't necessarily mean that you don't have milk ducts, but that they haven't matured by whatever the usual processes are (during puberty, I'd imagine). I'm sure that I've read that the hormonal changes of pregnancy and childbirth, and the stimulation caused by each infant who tries to feed at the breast, can kick start a few 'late bloomer' milk ducts, and that in some cases this increases supply to the extent that exclusively or mainly breastfeeding is possible. I sincerely hope, if it does turn out that you have THB, that this is the case for you.
Kelly - your post was lovely and supportive, but you're mistaken when you say that OP didn't make it clear whether she wanted to breastfeed or not - the first line of her post says that she is "desperately hoping [she] may be able to breastfeed this time."