Some advice needed

So I have a baby with my current boyfriend of 2 years he’s almost 5 months old . My boyfriend has 2 daughters from a previous relationship he’s still legally married but they’re separated that means they can date . When I gave birth I told him I wasn’t going to give out son his last name since he’s still married and I feel some type of way about it . Well he promised to get the divorce done this year so I ended up giving my son his last name . Well his ex told him she was going to pay for the divorce since they both agree on it but he doesn’t have the money for it well now she told him to deal with the divorce himself. The divorce hasn’t been done these months bc of the virus and the courts were closed he has the paperwork but he says he wants to hire a lawyer to fill out the paperwork for him . We recently got in a argument bc i asked for the divorce again and I told him he has until this year if he doesn’t get it done then we’re through I’ve been asked him to get it done and he just kinda brushes it off he says it’s jus a piece of paper but I don’t feel good knowing he’s still married. He asked me for more time but I told him since they both agree on the divorce it shouldn’t take more than a year and courts are open again . So I’m wondering how long do divorces take and cost here in California if anyone can give me more details about it I would appreciate it