Try a travel agency that specializes in arranging cruises for solo travelers.
www.singlescruise.com would be worth looking at. I've sailed with them on 3 occasions. They will pair you up with another single cruiser. They have parties and events that are just for their group. It's loads of fun. No, it's not the love boat, and you will probably not find your soul-mate, but you will be among a group of very fun, good-natured singles who enjoy cruising.