H1 is on 221g from oct 2019 , Applied for H4

Hi ,

I’m on H1 b got 221g on oct 1 2019, We submitted all the documents but no response. They again asked for client letter in Jan we submitted again , Then again asked the same on Feb 26 submitted again but no response after that consulates are closed .
Now as it’s been more than a year , and because of my wife’s health issues , I applied for H4 on a emergency visa bit again got 221g to close the open H1b with the consulate . But the consulate is asking to withdraw the h1b petition.
1… In order to file a H4 do we need to withdraw a approved H1b petition from the consulate ?
2. If so how long it will take to with draw a petition by the employer?
3. after withdrawal of H1 b petition by the employer with my request , Does that impact my future employment on H1b?
4. Can I find a new job and file a new H1B petition after coming to usa ?

Thanks in advance!