I understand how you feel and I really think that you should return to work when you feel ready. I'm also a working woman and I love my career. It has helped my GD significantly to have that part of myself for a good chunk of the day. I really think that going back to work averted a complete crisis on my part. I took 12 weeks off, which is what my employer offered me paid, and although I probably could have negotiated an additional 6 weeks of unpaid leave, I'm so glad that I didn't. By the 6th week post-partum, my GD was so bad that I was flipping out every single day. And it's not like caring for the children was all that difficult. The older one went to preschool from 9am to 4pm every single day and my husband, a teacher was home by 4:30pm. Obviously, I had it good. But my mind was racing all day long. The day I set foot in my office again was the day that I was able to set aside my anxiety about being an all-girl mom and remind myself that I more than an all-girl mom and more than a mom for that matter!
Don't get me wrong - I LOVE the toddler and baby stuff. It's hard work to be the kind of working woman that I want to be AND the kind of mom that I want to be. I wake up early to pump every morning and I'm the last person to go to bed each night. From the second I get home, I'm greeted by sheer madness. But I really enjoy the challenge of trying to balance my dream career with my beautiful family. Something about that struggle reminds me that I'm strong, capable, and worthy of the things that I want in life.
I still have pretty bad GD, however. I wrestle with it every day. But I'm able to turn it off more now that I'm back at work.
The thing that frustrates me about your situation is that is the idea that if you want to work, you must not like being a parent. What about your DH? He didn't arrange his career around having a child - that's why he can only take 2 weeks off. Would anyone accuse him of not enjoying being a parent? It's really not fair to expect you to make all of the sacrifices just because you're the woman. Look, I understand that women generally take on more of the child care in the early years. I'm living that life completely - that's why I'm always go, go, go and I'm perpetually exhausted. But no one had better accuse me of not enjoying parenthood just because I don't want to stay at home with my kids all day long. No one would ever accuse my DH of that so they had better not accuse me either.
Anyways, I think you should work when you want to. If that's 3 months after your DS is born, fine. If that's 8 months after he is born, fine. If you want to be a stay-at-home mom, fine. But if you want to work, you'll be a better mother if you feel personally and professionally fulfilled. You'll be more engaged with your sons when you are home if you have time to develop the other parts of yourself that mean so much to you. You'll feel resentful and battle GD a little bit better if your career is flourishing. (Just to be clear, this is only IF you want to work. If you don't - and many of my friends don't - more power to you!)
If you're husband asks, tell him that one of your IG buddies credits returning to work with sanity. And since you're apparently already crazy, don't you need all the help you can get? 
Congratulations on your DS! I would have LOVED to have two boys!