challenging my employer/reasonable adjustment

Hello, an update on my first post (I cant find it). Received diagnosis in March this year; to cut a long story short I have been through a long and difficult process of meetings with managers and occ health appointments; not out of the woods yet. Had to enlighten (or try to) management that it wasn't a case of 'how has he managed all these years but its an issue now'..explained that I had not managed, have masked and winged it all my life, and now that the pressures of work are increasing and we are subject to quite intensive micro-management, my mental health is suffering and I am exhausted. Anyway, ASD diagnostic assessors and occ health report recommended a number of adjustments, and then a second occ health report recommended a reduced workload (they hadn't been as explicit in that recommendation previously).  Occ health looked at the adjustments I had been granted and pointed out that these were basically nothing that any of my colleagues could not have. Then management have refused point blank to let me reduce my workload (and occ health pointed out that management can not possibly give me the processing and recovery time I need whilst expecting me to carry the minimum required workload the same as everyone else, so where is the adjustment? Management have also said that I will be expected to take on more work and that the service can not accommodate me working a reduced workload. Furthermore, they threw it back at me, saying it is my responsibility to access staff counselling, Remploy, etc; they are essentially treating this as if it was a mental health problem that can improve with counselling and advice; I know counselling is helpful but the fact remains that I will not be able to cope with the expected workload; this suggests to me a lack of understanding of autism. In the last few months I have felt very upset, anxious, and had periods of feeling very depressed, hopeless and desperate, feeling as if I have no plan B, no options and trapped in a situation I know will make me unwell because of the overload. at one point after the latest meeting, which I found upsetting and offensive, I actually considered suicide and thought about how and where, even getting beyond distressed and feeling numb and calm about it and doing a sort of practice run; this has really shocked me as I have never in my life felt that desperate. I pulled through it and generally have much to love and enjoy in life. I am going through the motions of seeking union support, counselling and trying to contact the NAS helpine and Remploy, but as we all know, you can spend a lot of time chasing up and its hard to get through to anyone. The bottom line is that whilst all of this might help me get through, I'm going to have to fight with my employers and I think (may be wrong) that if I am placed at a disadvantage by being expected to carry the same workload as a person with out this disability, that could be discriminatory.

One other thing; there is to be a conference to formally discuss my needs and what my employer is prepared to do; I'll need to be advised and be assured that if the decision to refuse a reduced workload is final and I have to agree to struggle on with regular reviews and so-called 'support', will I have any protection further down the line if things go wrong with my work, or will it be a case of 'you agreed to this, you had the chance to look for another job' and therefore subject to the normal disciplinary procedures.

I'm not sure if it is safe for me to say what my job is and who is my employer, but you might be surprised. Sorry for rambling, hope this all makes sense and any advice would be helpful. I should also say that I already reduced my working hours two years ago (or I would have left), but I can not afford to reduce my income any further.

Thanks for your patience.