I'd suggest when you go back to work, making sure you have a good but healthy breakfast (not easy when you have a baby to sort out, I'm sure) - muesli, fruit, wholemeal toast etc, and taking a healthy packed lunch and some fruit to snack on if you think you'll need something extra during the day. Then aim to cut out all the unhealthy snacks, sweets, crisps and so on. Try to get out of that mindset!
In the evenings, look at portion sizes, try to train yourself to eat a bit less, especially of things that are obviously fairly high in calories, and try not to have second helpings.
If you love tasty food and hate cooking, does that mean you get a lot of takeaways or buy ready meals? Most of those not good news for weight control .... do you think you could build up a repertoire of a few suppers that are very simple but also tasty? I've noticed when people ask for suggestions in the MN recipes messageboard, there is always a good response.
I've struggled with my weight all my life, have lost and regained quite a lot several times, but when I do manage to lose, this is what I do and it works for me. Good luck and congratulations on your DD!