So, your mind is made up, your son knows what is going on and what is going to happen.
Leave now then. Don't expect your son to live in the same house as his father when he knows this is happening - make the break - nothing underhanded - lay it out on the table for your husband.
Do you have possession of the rental house immediately?
Do you think that your husband will let you take some of the household furnishings? I know, I know, he doesn't sound like the reasonable type. So, you either take some stuff while he is not there and piss him off to no end, or try to piece together enough stuff from second hand shops, auctions, friends etc. to get by until you can put it together a little better.
Very little value is placed on household contents when your dealing with division of assets - it's more the hassle of it all. But, half of the value of it is theoretically split 50/50. Is that what you want to do?