Filing a new I-130 is the best way to proceed.

Once you are a United States citizen and file for your brother and are eligible to apply for your parents in most situations that is the way to...

K1 VISA

The next step is to be scheduled for the appointment for your fiancé. Check the consulate website for updates and information about visa issuance.

Can H1B visa holders go back to the USA?

Yes you may return as a travel ban does not impact persons that held the visa prior to the date of the travel ban.

As my colleague recommends you need to check the DOS reciprocity list for document availability.

Do I have to wait to apply for my citizenship again if I was denied for failing the test?

You may file immediately there is no requirement to wait.

Am I classed as having any overstay or illegal presence?

Since you filed a timely application for extension both at the first instance and the second instance you do not have unlawful presence in the US.

Which document I must submit to prove the relationship Between the sponsor and the household member?

Depends on the relationship that you are trying to establish with documentation. For example a marriage you should submit the marriage certificate.

USCIS Form instructions to I9 “You should not reverify U.S. citizens and noncitizen nationals, or lawful permanent residents (including...

The B- visa application is likely to be affected by the pending I-130. The I-130 should not be affected by the B1 application. In order to receive...