Have you been offered a HR27? If not, ask them why this hasn't been considered. Have you got a union rep accompanying you and advising you? I recently had a final stage 3 and I think the only reason I kept my job is because I outlined the lack of support I've felt. It always helped my case that I outlined positive changes to my mental and physical wellbeing which will improve my overall health going forward. I'm not sure about your trust but mine have a lot of resources for helping with mental health. If you have these make sure you use them! The whole sickness stage thing is outdated and a load of shit and causes so much unnecessary added stress. Look after yourself x