Oh, getting verification of the modules you've completed would be no problem. It would be up to the university you wanted to attend to decide whether or not to accept them towards the particular degree you wanted to do. Mostly that decision would be based on how closely they mirrored the content of the compulsory modules in the degree (although anythng would count in place of open choice modules).
The 'restricted status' only applies to the OU. It's an internal policy. You'd be eligible for normal student funding like everyone else in the country as you don't already have a degree. It would be loans but you may be entitled to bursaries etc because of your disabilities and low family income. The loans aren't necessarily as scary as they sound, as you'd have to be earning far more than you do now to have to pay them back. You can get funding for PT study now too, so that might be a route to explore given your health issues. Universities are much more disability friendly now and can provide all sorts of support (and help you access funding for this).
Grockle: I have no idea if I've been tested for lupus. Probably not. They took loads of bloods at rheumatology (they always take bloods) but I think they were testing for the stuff that indicates ankylosing spondylitis. Maybe I'll ask about lupus. The rash is more subtle than in most of the photos online, but it is annoying (and more annoyingly the rosy cheeked look makes me look far healthier than I am, so long as you ignore my eyes). I certainly have symptoms (but so many AI conditions share symptoms): plenty of fatigue, joint pain (but no damage), rashes, muscle aches, fevers, memory and thinking issues, chest pain/difficulty breathing (but no wheezing), mouth ulcers, some dizziness, etc. So it might be worth checking out.