what would happen if they make gay marriage illegal again?

If by "they" you mean the Supreme Court, it would go back to the states as it was before Obergefell v. Hodges. Some states would allow it, others would not. Exactly the same as what would happen to abortion rights if Roe v. Wade was somehow undone.

Nothing, since they won't do that, and that is not really how the process works.

They need to get the government out of my life. They don't have any moral authority to marry people. That is a religious tradition. It should be up to the individual who the want to marry and up to the individual who they want to recognize as married.

Itll break families apart who are gay. It's not fair to do so.