I am really sorry to hear your situation. Here is my case, and hope it is helpful:
I tried to withdraw my case by sending IRCC a web-form, and they replied very fast with detailed instructions of the withdrawal process. However, I decided not to withdraw my case after consulting with immigrant consultants. Then I sent another web-form asking IRCC to discard my previous withdrawal request. Per GCMS notes I received, they have notes about all of my requests, and they have discarded my withdrawal request and continued to process my application.
In terms of your situation, I would suggest you seek help from an immigration consultant and highlight the urgency of your case. I believe they will provide more professional suggestions as I am not familiar with the process of submitting a new application.
Hope this information is helpful to you, and good luck with your application!