There are plenty of people on this forum with the expertise and experience to advise you but here's my two cents for what it's worth:
When you say the only things missing in your relationship are love and sex, I have to wonder what that leaves you with? In other words, the situation is not at all good. First and foremost, I would definitely include her in the process of getting to the bottom of these issues; she needs to hear from you everything you've expressed here. Perhaps couples therapy is warranted or getting her doctor to try a different medication. You need to be proactive about it, get online, as you've done here, and find out as much as you can first, so as to be well-informed prior to seeing the doctor. I think that's true of any malady these days, there's so much info online that it is almost inexcusable to not have done ones' homework.

To me it sounds like a clear case of untreated depression, post-partum or otherwise. Also, not surprisingly, one of the side effects of pristique is changes in libido. I'm quite certain your wife is not lazy. And I'm also certain that your bodybuilders physique has not so radically changed as to turn her off. Address her depression and I think things will look up for you. Good luck.