If you signed for the vacuum, it's your vacuum, sweetie. You're responsible, and if it means you're done with that louse of a husband, you're getting off cheap.
Little kids, eh? Ever think of having their friends stay with you as an informal day-care center? It won't bring in much, but there are many at-home employments available if you cannot get out.
Don't blame it all on him. Don't blame it all on yourself, either. Neither process reduces your vacuum debt by a penny. Work on solutions, and let his girlfriend keep the vacuum and the person who brought it over.