From the picture provided, it does not appear that your Macaw has a damaged beak. Green Wing Macaws are very hard on their beaks and love to chew on wood toys, when chewing, the really scratch up their beaks. this is normal. My Neleno's beak always flakes off, chips in some spots, even bruises sometimes. Their beak grows fast so don't worry about the appearance of their beak.
I am very concerned about his diet, this is more important. you must find a way to increase fresh fruit and veggies into his diet, even if you have to hind them in other foods. Like Parrot bread mix, mashed sweet potatos, mix in some almonds. I would also advise you to give your Macaw 1 hard boiled egg with the shell but remove the yoke, this is very good for their beak and feathers. i would give him 1 hard boiled egg 2-3 times per week. this is also good for when the Macaw molts.
I found out by playing with my Macaw, I would give an almond for treats and ask my Neleno to perform a task, when he did, i would reward him with the almond, then I would ask for another task, once he performed that task, i would give him a pea, he hates peas but since i made a game of it, he ate knowing that he did something that pleased me so therefore he was happy to eat the pea. Now peas are offered and i don't see them on the bottom of his cage like I used to. You can also hide other fruit and veggies inside a paper towel roll, bend both sides and make them work for the reward inside, place some almonds and some fruit or veggies they don't like, when they find them and open the roll get excited and say what a good bird they are and they will eat it to please you. best of luck Joe