Quoted for truth.
It's harsh - but I've seen and heard plenty of stories involving Asian students who thought that they could survive here. The ones that did survive are the ones who had rich parents who didn't need to borrow the money for their fees.
how much will i earn in a week
Maximum of 200zl a week. I'd also doubt that you would have any chance of passing microbiology in a Polish university if you work full time on top.