As an OU student, I can vouch for the fact that you can get help with your course fees, be that spreading payment or the award of substantial grants and bursaries from their 'hardship' funds. You may also be able to get a small grant from your LEA to help with certain costs - travel to residential schools etc.
The only problem is that the OU doesn't offer Art as a subject, although it does offer a wide range of courses on History of Art.
Go to your nearest main library and see if they have a copy of the Directory of Grant Making Trusts. It's a bit of a trawl, but it lists literally thousands of organisations that people can apply for grants from. I once got �20 towards the cost of books from a local charitable trust that gives grants to mature women students. Doesn't sound much, but every little helps, as they say on the Tesco ads.