Really feel sorry for what you're going through right now. It sounds horrible. I'll pray for you tonight.
I understand what you mean by wanting the SN to give you confidence/peace without taking it immediately. I've had mine for a few weeks and I still don't know when I'm going to use it. However, it really does give me peace of mind knowing I have a way out.
It seems like your husband isn't a very good person; he manipulates you and uses you for cleaning his house. Sorry to hear about your anxiety. If you want to obtain SN, you'll probably have to order more. I doubt he still has it. When you order the SN, buy it from a seller who gives you a tracking number. That way, you can know exactly when it comes in. If I were you, I would order to your house and wait until the tracking number says it's going to be delivered the next day. On that day, wake up earlier than him and get it as soon as it's delivered. That's one way to do it.
Another way would be to send it to a neighbor's address and act like you accidentally entered their address so they would give you the package.