I was in a high paying govt job. After DD#1 i, like you, intended to go back to work. I did, when she was 12 months old - just part time. I hated it. Its amazing how you have different wants, different aspirations, different attitudes when you have children.No longer was i the high flyer corporate woman whom didnt mind staying back till 8pm, who didnt mind getting to work at 7am, who didnt mind work, work, work.
I lasted 7 months - and quit. Dh and i made the decision (thru a hell of a lot of tears and sobbing by me to actually let go...) that i would be a SAHM and bring our children up, he would be the breadwinner.
At the end of the day, your taking 4, 5 years out of your working life......seems entirely worth it if you ask me...

I havent looked back. I thrive on being a SAHM.......