I am afraid that if you decided to do an Access course there would be no benefits, grants or other financial support available to you that would not already be available on a household income of £22,000 (I've been in pretty much an identical situation but with 3 children). With 1 child that may mean a little bit more tax credits than if you were earning yourself. Your household income would be too high to claim anything extra.
The only possibility would be your husband could get 25% sole occupancy discount on your council tax, but with Access courses being 15 hours or less a week local authorities on the whole don't deem you as a full time student for this purpose.
Once at uni, with a household income that low you would get the maximum available support, which would be just over £7k a year if studying outside London, plus a university bursary (which varies with the uni, but are generally worth £1k+).
It's just that year before Uni where you need to gain the qualifications for entry that's totally un-funded. If you can't afford that you could look into studying a unit or two from the Open University part time.