undocumented bf got in car accident with my car - need car insurance advice

Hello everyone, my boyfriend used my vehicle the other day and got in an accident totaling my car and damaging two vehicles and the outside of a property a couple of days ago. My boyfriend doesn't have a license or his own car insurance. I wasn't present when the accident happen, the police were involved and took my car insurance information and passed it along to the other parties involved. I have papers and basic car insurance. I was told to not file a claim but just received information from my insurance that someone did file a claim. What should I say to my insurance? Is there anything I can do to make this less bad with my insurance I live in California. any advice is welcomed thank you