"I have not made a decision regarding legal seperation or divorce yet." ______________________________________________________________
You were legally separated on the day you moved out. That is how it works in CA. When you say, " I'm outta here" and move out, you're both legally separated in CA. and in the eyes of the court. ____________________________________________________________
"After a consultation with a family law attorney, he advised that I file a supplemental declaration. In order to explain all the past emotional, verbal and physical acts of abuse." _____________________________________________________________
It depends on what your plans are. If you're leaving, then file for a TRO and use that to make your declaration. Just filing a declaration with no pending motion serves no purpose, IMO. The court will not even read it because it has no reason to. You need to file some sort of action and include the declaration within the action, such as filing for divorce, filing for spousal support, asking for a TRO, something like that.