Hi Philippa, didn't want to leave your post unanswered.
I am a sahm too, my boys are much older now, aged 6 and 3 and at first I did return to work after ds1 was born.
I had almost a year off work, then he started nursery. I would tell everyone how much happier he was there but he wasn't, I lied because I wanted everyone to think that the choice I had made was the best one.
When I became a sahm when ds1 was 16 months I felt it was the right thing for me and him. I didn't care what anyone else believed. Everyone is entitled to an opinion and everyone feels like they are defending their decision.
As parents we are dammed if we work full time, part time or stay home. We can't win.
Staying home in the early years is hard. It is hard to get structure into the day, it is hard to finish housework, it can be mind-numbingly boring too. I think it is just like any other job, there are good bits and there are crap bits.
I found music helped a lot, get them dancing to stuff you like, do housework to music. Music can really alter your mood. When I got really mad with things I would jump up and down to music to calm me.
Also I had some "me" time, whether I chilled in a bath, went out in the evening to meet friends, learnt new things either on the internet, watched dvds or programs about things that interested me.
I have an amazing dh who is very hands on so I can go away for a weekend to see my best mate who lives 100 miles away. It helps.
Re know-it-alls, nod and smile