I am completing my second year of the Bachelor of Psychology course this year at Monash, I haven't completed any coursework at Melbourne so I can't offer advice on that sorry, however as you wish to do creative writing as well, have you looked at the course layout for the Bachelor of Psychology at Monash?
http://www.monash.edu.au/pubs/handbooks/courses/3883.html (The requirements section has the basic layout for each year)
The course becomes very Psychology heavy in third year with no room for non-psychology electives, even in second year you only have a maximum of three non-psychology electives. If you wish for creative writing to be your major (e.g. you don't want to peruse psychology for another ~3 years to become fully qualified), I'd lean towards Melbourne if it is your passion, as at Monash your non-psychology electives in the Bachelor of Psychology course are limited.
Try not to let the scholarship sway you too much