That's like 2 a week on average right? That's manageable isn't it?
I'm not doing an arts degree, and the only assessments I have are lab reports, online quizzes or actual exams. But seriously - I think this is relevant to any degree - give yourself a set routine, and stick to it. Have deadlines for completing different components of an assessment, and keep up-to-date with lectures and summary notes.
When you find you're falling behind, knuckle down and work until you're a little further ahead.
And most importantly, give yourself time away. Even full-time uni doesn't take up all your time, so try and give yourself a block of a couple of hours on the weekend to go for a walk, catch up with friends, or do something that makes you feel human again =)
... on that note, I'm heading to the beach =P