Hiya,
I can sympathise, although I am enjoying being a SAHM, it would be nice to have the option to do a few hours work a week.
We don't have rellies near either, and don't qualify for working tax credit; plus OH works a fair distance away so is out for long hours. When I had Daisy 6 years ago I worked for the NHS, and I could have gone back but in the end we decided against it as after the childcare costs, tax etc, I would have only been bringing about a pound an hour home, and it didn't seem worth the hassle.
As the others have suggested, you could look into doing something from home. This has always been my intention, and now money is getting tighter there is more pressure to do something about it. I'm planning to invest in some ceramics equipment when we move as I've always been told that I could sell my sculptures (haven't done any for years though). I think one of the things that's kept me sane is attending one or two baby/ toddler groups a week - I've made a couple of really good friends and it's lovely to have a chat with other mums and have someone else make you a drink for a change!!!
All the best,