I'm a nervous wreck as well...My Harley who is almost 7 mos is scheduled to be neutered April 16...I have a play yard that I will keep Harley confined to during his recovery.
Maybe you could get a baby gate and confine him to a bathroom or laundry room or even an old baby playpen...I've seen them at goodwills or thrift store pretty cheap.
I got my doggie play yard online thru Ebay....They are great for confining them during potty training so they don't have run of the house...and when you just can't watch them and when you visit family and friends to keep them confined so they don't have any accidents in there homes...when you need to run out to the store or out to dinner...I always confine him when I go out for his safety and the safety of my stuff LOL....He will graduate one day and not need to be confined but until than.
Good luck with Keno surgery.
PS...don't forget to get a blood panel done before his surgery...its to make sure he can handle going under anesthesia...that there is no underlying problems with him...Very Important!!