Thank goodness the surgery part is over. You might be able to discuss with work if there is project work or alternative type duties that can be done other than your normal job. I know I didn't feel emotionally well enough to work, as well as the physical aspects on chemo. But we are all different.
Once I completed chemo and recovered somewhat I have returned to work as a nurse in a graduated plan...with supporting medical certificates and have a plan drawn up. I currently am working 4 days a week 6 hourly...so have a mid week break. My sick leave hours are currently unpaid but that is okay.
You might find this link helpful. But Gov depts definitely have obligations to get you back ASAP...they even offered I do 2 hours a day during treatment but I declined...feeling i needed the time to put myself first for once. When I returned I felt ready and am once again an important part of the team.
http://employsure.com.au/blog/management-of-non-work-related-injuriesillnesses-employers-health-and-safety-obligations-relating-to-employees-injured-outside-of-work/