I think that Disability Living Allowance is a possibility. To claim others it may depend on your National Insurance contributions. Why not call in at a Job Centre and ask. Better still, find your local Citizens Advice Bureau - CAB - as they can be really helpful.
HI I HAVE ARTHRITIS OF THE SPINE AND ONLY WORKING ONE... - NRAS
Benefit entitlement really depends on your contributions, you may be entitled to Tax Credits which depend on circumstances, there's also DLA (Disability Living Allowance) but this may be hard to claim if your self employed, it really depends on what work you do. There's also housing and council tax benefit you may be entitled to.
As your only working one day have you thought about stopping work and claiming ESA for now or at least until you feel able to return to work full time.
As Phoebe has said the best place to give advice is the CAB or another welfare rights organisation in your area. I've added a link to a benefit calculator where you can enter your household income/circumstances and see what your benefit entitlement is.
My OT suggested I claim ESA as I'm a self-employed artist. Haven't the stomach for it all yet so living off thin air and husband's meager salary a bit but plan to look into it all soon as I feel well enough. TTx
The link Beth58 has posted looks great but it may also be worth calling the Benefits Enquiry Line as they should be able to give you a good idea of what benefits you may be eligible for. Their helpline number is: 0800 88 22 00 (8.30am - 6.30pm, Monday - Friday).
I had an awful lot of help from the disability welfare person at the CAB. they were really great, helped me fill in DLA, but also made sure I knew about all the local council travel concessions, council tax benefit and things. It really helped a lot, and they do know what is available that you might not have thought about.
They could also tell you about working tax credits too. You need to be working at least 16 hours I think for that, but that could be something to think about.