Ooookay, weird, second try on this.
A fully masculinized brain that can be attracted to women basically can work on visual queues alone. Boobs or butts snap a guy's eye to them like they have magnets inside. It's just the way that a male's attraction reflex works. In milliseconds, a guy can pick out whether he finds the woman attractive or not. This was largely the case for me, pre transition. I've always been able to see guys as attractive but there wasn't that instant "OMG LETS DO THINGS IN BED" reflex so, I knew something about the other side of attraction before transitioning.
After about six or so months on HRT, the visual reflexes went away. Boobs and butts and curves and pretty faces just stopped being something that I'd notice unless they were particularly stunning in some way and, even then, it was more a 'notice' thing rather than an 'attraction' thing. Guys steadily got more and more easy to admire and girls didn't diminish, per se, so much as the auto-objectification that a masculinized brain pulls off just disappeared (OMG YAY).
I'm pretty eager to engage new people personally and, what I found is that, when meeting someone new, I had to *like* them as a person before I could even start to look at them romantically or sexually and I had to want them romantically before I'd want them sexually. When you look at it, it's a pretty standard pattern of female attraction. Now, over time, I was able to find ways around this, for example if I was just itching to get laid and wanted to do something about that (this almost exclusively applies to wanting guys in bed) but, really, when it comes to someone you want to be with on any kind of real level, they have to pass through the gates.
Now that I've been there and done that for a bit, what I find is that the instincts that put all those levels of attraction in there are something I can trust. They're comfortable and make it easy to not treat the world as some kind of bizarre smorgasbord of possible hook-ups. They also make being friends with girls and guys really very easy because, unless a friendship blooms into something more, we're just people and not romantic objects.
That said, once *in* an attraction to someone or *in* a place where I'm open to someone sexually, objectification can and has happened so, even still, I try to make sure to focus on the person and not the attraction right up to the point where we're lost in the moment.
Hope that this explains things a bit. What you're going through is normal and typical but it *is* a new set of plumbing for you to figure out even before you have the pipes refitted, so to speak. (ha HAAA... analogies)
P.S. - Alllll that said, my sex drive, even on a full and very steady dose of HRT for four years? Completely fine and still very high or higher. Just works differently.
P.P.S. - learningtolive: I'll say this. Being with a guy pre-op can be wonderful, you just have to open yourself up a bit while accepting where you're at in your transition process. Word to the wise though: practice beforehand. Making love in that way takes some getting used to. It also takes a good deal of lubricant so, read up of you're going to try. Juuuust my 2ยข on that topic.