Student Visa (F1, F2, M1, M2)

I came to the USA in September 2016 on H4 visa and started going to school from January 2017. I applied for a change of status H4 to F1 in June 2017 and my H4 expired in October 2017. I got a denial from USCIS with the reason that my H4 expired before 30 days of my program start date. I initially applied COS for August 2017, but my University deferred the start date to January 2018 and August 2018 subsequently. So, my COS is denied as I could not maintain my H4 visa while COS is pending. However, I traveled back to my home country immediately after COS denial and would like to apply for an F1 visa at a US consulate here.
In this situation,
1. Does my SEVIS id change if I apply for an F1 visa now?
2. Do I have to pay SEVIS fee again?
3. What happens to my previous SEVIS history if that record is terminated after COS denial?
4. Is there any way that I can transfer my credits from old SEVIS id to new SEVIS id?
5. Do I face any OPT issues as I only have a semester left?

Thanks,
Deepthi.