Keep OH updated with any changes in your health.
Get your union rep involved with all meetings, and start a record of what happened, what has been said by people, what 'suggestions' have been made by management etc.
Also, you need to ask for a personalized risk assessment, specifically so that you have it in black and white what accommodations or special equipment they need to supply to ensure that you are not disadvantaged by disability when doing your job. (There is NO excuse for the NHS not providing this due to the 'size' of the business !)
Begin it with the walking distances from car park (if you arrive exhausted, it makes the whole day worse), any pain/discomfort due to working equipment (chair/desk/computer/ lifting/carrying etc), difficulty speaking at length (How can this be alleviated e.g typing instead of talking emails/Teams chat etc etc Is there a piece of equipment which would help - ACAS is great for this)
Asking for a reduction of hours due to disability IS 100% a 'reasonable adjustment' ! (I had the opposite, where managers wanted to cut my hours, but I wanted to remain full time, but needed specific equipment to help me)
At the moment, due to disability, I have personalised risk assessments done for different sites I work at. I have to have a chair with armrests, a foot support, a back support, a wrist support, an adjustable monitor screen (no laptop use), disabled parking spot (and a procedure to follow if the disabled spot is in use) and I can only travel a certain time/distance to get to work etc
This means that I have it in black and white that I cannot work at sites that are too far away, or that do not have EVERYTHING that I require ready and waiting for me. It also means that I am not EVER having to put my health at risk due to any whims of managers needing to staff different areas. I can just say 'No'.
It took a long time, and LOTS of Union help to get everything into place, and like you, managers were initially trying to demote me to an admin post or trying to get me to leave of my own volition by saying 'well if you're not fit to go wherever I send you, then you're not fit for the job?'
I just kept having 'meetings', kept being re-referred to OHS, and kept an entire diary of emails/meetings/phone conversations etc etc until eventually I did a formal grievance. THAT was the turning point for management, because I had evidence of ALL their attempts to disregard their own bloody |Equality/diversity policies (as well as Health & safety/ Staff governance/Grievance policy/ Workforce policies investigation process/Bullying & harassment etc
Begin by completing an 'Am I being bullied at work reflection tool' (In Bullying/harassment Policy). Then look at the other NHS policies, and highlight areas that are relevant to you and your situation. And get your union rep involved asap !
It's a long slog, the NHS moves at a snails pace, but it's worth it to ensure you keep your job (and to force the NHS to practice what they preach by honouring their OWN policies !)