I am always thinking about alternative marketing for your place. Shafston GH. may have some ideas for you. When I was there, the owner offered a wide variety of accommodations. To make it affordable for the budget traveler he had a hostel type situation where folks would share rooms and bathrooms. I know his business was all through German travel sites and hostel sites. I have another friend with a guesthouse that gets a lot of business through the hostel sites.
You may have tried this. Your place is so lovely. In these tough financial times perhaps people can afford to come if they can bunk up. I know that is a lot of work and your place may not be set up that way. Perhaps you can make one bunk room and try it out. You may already have... just an idea brainstorming for you is a good way to avoid my own work. lol.
At the time, he did a meal plan and the folks there were very happy. He attracted the back packer crowd, people who go to Jamaica for day time adventure, not the night life.