Maybe you could talk to him, and let him know you scared to leave him alone. Like a good talk, not a accusing talk. Ask him about it. I know for some people being alone triggers issues, but it seems like your husband keeps himself pretty busy. Maybe he could share what his plans will be for the 2 days. I would think that 2 days of fun would be great for you (even though you might worry a bit) It is not like you are leaving him for a month.. you know. I just think talking it over in a positive way might help. My 2 cents
keep us posted, and take care