The thought was far worse than the reality.
It is hard at first - both through missing your baby, and also through trying to work out how to manage everything that needs doing around the house. Someone on MN told me to expect the first few months to be terrible, and that helped, mainly because while they were hard, they're weren't terrible, and so that was a surprise.
But it does get better, it really does. The first few weeks I thought about DD a lot, and then I used to get worried when I didn't think about her, as if that meant I didn't care as much, which is bull, obviously. But the thing is, work isn't a place you associate with your DC so it's not like being in the house and they aren't there - work is a baby-free place, so you aren't reminded of them as much. And then you start to see how much they enjoy spending time with their dad, grandparents, childminder, or at the nursery, and that's a nice thought to cling to.
Be kind to yourself, though, as it is a big change. There's been some great threads about how to be organised and keep on top of life when you're back at work, they're well worth reading. Though the key things are a) batch cooking, and b) getting everything ready the night before 