How do I motivate myself to write my essays?

I have gotten really behind with work for uni and can't seem to motivate myself. I am on anti-depressant medication and have talked to my lecturers about the depression. I am going to apply for agrotat exemptions for my exams in case I don't p... and I don't have to finish a few other small projects, but I still have two essays to write and the deadlines are coming up soon. I have had a really long time to do these essays, but I still can't motivate myself to do them and when I sit down to do the first one I can hardly write anything at a time & it doesn't flow properly. It is like I have writers block or something - someone please help me! How do I motivate myself to get these essays done? How do I decompartmentalise them into smaller tasks?