Trying to get my workplace to understand me, and I need help?

Hello all!

I was recently diagnosed with autism at the age of thirty.

This has been a huge rollercoaster of self-discovery and understanding as I come to realise that I'm not broken or wrong, but different.

I currently work for the Civil Service and I had been on a several month long period of absence, I have returned to work on a phased return and I am expected to do one day in office. However it has now got to the point where my phased return has ended and I am back to full hours but have yet been able to make it into the office. They expect me to be in office for the full hours of my phased return and denied my request to just do a half day. I really struggle with office and with just going outside in general as I find it all rather overwhelming, on a good day I can manage, but it requires a lot of energy which then leaves me completely drained for days. There is nothing in my role that can't be done from home, I have had an occupational health assessment which suggested that if I was unable to work in office they should consider home based working, however, to this day, they are refusing to let me work only from home and are not providing an adequate reason. I do not feel that the management of my office understand me and how hard this has been, it is not only causing me large amounts of stress but my family and friends as well as they try to support me.

If I'm completely honest I am struggling quite a lot and I feel I'm at the end of my tether. 

For a bit of background I had to leave my previous job, before my diagnosis, due to it's impact on my mental health and the manangements archaic attitude (thankfully that manager was replaced). I have always struggled with school and work and how much it drains me and causes me pain but I didn't understand why until recently.

If anyone has any suggestions, advice or just words of comfort/understanding they would be much appreciated.

Thank you for taking the time to read through this, I hope you have a nice day.