Set small goals and reward yourself regularly. That makes it easier to sustain the task of drafting until you have done enough of the writing to have a stable basis for completing the assignment. It gains enough energy to attract more. It gets completed effectively and creatively. This may happen in a single burst of drafting, or it may happen during a second or third round of redrafting and revising, or even after the project has been allowed to sit for a few hours or overnight.
Writing is like making bread.
You'll find all of this rewarding. To the General Orientation main page.