Big I was like this with my first and you know what.. i worked in CC too. I am not saying you should do what i did but I quit work when my Ds was 11 months old.. yes I would get cranky at an 11 month old.. I was tired and i had spent all day with kids (him included as he came too) and was simply over it by night time..

don't feel guilty.. Being a mum is a tough job. is there anyway you can take even 40 mins to yourself at night before you deal with DD? not just the drive home or whatever but once you get home.. have a cold drink and take a book and go read in the backyard or something.. To wind down before your home life begins.. kwim???