DH and I always planned to have two children. We were both only children and didn't particularly want that for a child of ours.
DC1 is almost 17 months and I have just found it SO hard. The lack of sleep, the constant demands on my time and attention, and now the endless whining as we enter toddlerhood. DC1 is particularly clingy towards me and I find it suffocating at times. DH tries to help but most of the time DC just wants me and it's so draining. DC is upstairs with DH now and all I can hear is whingeing and crying and DH getting annoyed by it. 
Obviously I love DC, more than anything, but I suppose I don't always enjoy being a parent that much. I don't think I was prepared for how tough it would be.
Makes me wonder if we should realistically have another. Then I feel rather sad and that I must be a shit parent. 