Op is it possible for you to get a free half hour with a solicitor to discuss either keeping your home or forcing a sale so you can split the equity and secure yourself financially for a while?
SS may have resources for this though I'm not sure.
When I left my abuser I was renting so it made things easier so never undertook this route.
You've got this. Just go to the meeting, remember the only persons actions you can control are your own.
If your partner does not show up that can and will be held against HIM, not you. You just need to cooperate. They're there for yours and your children's protection.
I know it's hard to feel like you're not responsible for an abusers actions but that's because they've groomed you to feel like that. It's classic "look what you made me do" territory.
Go out, grab a couple of notebooks and pens, write down everything the solicitor says if you get to speak to one, write down everything social services say, write down any questions you want to ask now but might be too worried to in the moment to give you a prompt.
Remember your buzzwords, ask them for Protection and Support in Leaving.
His attendance will purely assist or (hopefully) desist him with any sort of visitation of the children, so if he doesn't turn up, good! It's what you want ultimately. The less he cooperates the less likely he is to get any sort of custody though that's another battle for another day.
Take it one day at a time. Just be a sponge right now. Soak up all the information they give you, and digest it later.