In what way? Finding stuff to do? Or DD under your feet all the time? 18 months is a pretty tricky stage as they are wanting to be into everything, but not quite big enough for everything they want to do.
Yes it does get harder but then it gets much easier. For a start they get better at playing on their own a little, they go off to some sort of nursery at 3 and also they start chatting and being more of a companion (at least some of the time).
I do work very part time but I love my time with ds now. I was quite unhappy when he was 18 months.