Fernie....I am certainly no expert..but do grow a lot of basil, it is my son's favorite herb and he expects me to keep him in full supply!
From looking at your picture, it looks like Genovese basil to me. I only have one Genovese plant
because the African Blue has a better flavor and is more hardy. I found a green worm on mine this year...for the first time. Mine looked exactly like yours...eaten leaves and all...I thought it was a goner. Try spritzing it with a solution of water & a few drops of dishwashing liguid...check the underneath sides of the leaves and make sure there are no worms, white fly eggs, ahids etc....ALSO...you may need to put some crushed eggshell around the base of the plant
. It may very well be slugs which you can only see at night. I think you can save the little guy...but I also wouldn't water it every day...maybe just every other day or so. good luck and let us know how it is going.