Legal Question in Family Law in California

If you were never legally divorced, you need to file and be granted a divorce before you can remarry. It does not matter how long you have been living separate and apart.

You only have to get a divorce if you do not want to be guilty of the crime of bigamy.

Yes. You are married until the judge enters a decree of dissolution of your current marriage. Remarrying again will render your second marriage void on the grounds of bigamy.