Off work with stress where do i stand?

I have worked for a small maintenance company for just over 1 year. I have had issues with another member of staff basically from the start she has bullied me and made lies up about me. I thought i had the backing of one of the directors as i had mentioned this to him on several occasions and he said he would sort it.......Nothing was ever done. I have to work in a building on my own i have no dinner hour and work half an hour more each day then anyone else in the company. I am not paid well and have found myself in some financial trouble and what with everything else going on i have been signed off work sick with Stress and Anxiety. However my creditors have been trying to contact me at work and altho i have told them i am off sick they have bombarded work with emails phone calls and text i am now being asked to attend a disaplinery for my use of eamils. I am dususted of how i have been treated as i have worked my off, have been bullied and basically lied too. Where do i stand?