Help, what should i do?

Hi, I was just wondering if anyone out there could help. I'm 32 and was diagnosed with cervical cancer at the age of 28. since my diagnosis I have under gone 3 surgeries the last one being in October 2018 the most radical of them all. I've been lucky to escape having any other treatment appart from surgery but have found mentally this has really effected my anxiety and my confidence as I am now  partially incontinent have nerve damage to my right leg and i find  myself constantly tired and fatigued. I do everything that's suggested of me, I do all alternate therapies as in massage and reiki even Crystal's I am on medication to help with my pain through nerve damage and do my daily exercise from the physio. to keep my brain active when I was first diagnosed I completed my degree and have  now started masters along side my employment that's full time ( and has been through out this whole ordeal) but i am on reduced hours from the doctor to only work 4 full days instead of five. I work in a busy school and I work with the younger children  I find this dosent help with my pain but my headteacher is reluctant to move me to an older age group. I have asked to see occupational health and have been given one appointment that was over an hour away in the car, when this date was given I wasnt confident that I was able to make the journey with out wetting myself and was  anxious about where the toilets where. So i asked my employer to cancel the app because of this reason. I am now waiting to be seen again for another appointment but local to my area but this still hasnt come through. I was given an ultimatum today that I would either have to come back full time or stay at 4 days a week. I felt that I had been ambushed by my headteacher and my debuty. I have tried contacting my Macmillan nurse but she is away I just need some guidance please help. Many thanks