I don't understand the logic.
You own an apartment. Your mortgage repayments are 1100 per month. Are you on a fixed rate?
You want to move, rent out your apartment at a shortfall of 200 per month, pay the nppr levy, the prtb fee, income tax, lose your trs relief,pay for repairs and maintenance and then pay the entire rent somewhere else. But somehow you think this will save you money?
Are you thinking of moving home? Or a really cheap flatshare? Because that is what you will need to do to make this worthwhile.