Gmail password changed by someone not me

My Gmail was stolen by a previous neighbour who changed the password and I can not get it back. I no longer have the same phone number associated with the account. I wouldn't care except there are pictures of my son when he was younger and my now dead service dog. Is there any way to get it back?

Thank you.

You can go to Google's account recovery page and fill out a form using the details that you know, e.g. phone number, passwords.