I have to ask...What are "Macaw Nuts"? Are you talking about just nuts? That's all you feed him are nuts? Or is "Macaw Nuts" another name for some other type of food?
Either way your Macaw's regular, daily diet should consist of a healthy, fortified pellet as his his main food, supplemented by lots of fresh veggies and dark, leafy greens, and then a small amount of a healthy, varied seed-mix that DOES NOT contain any sunflower seeds or peanuts...And then he should get occasional treats in very small quantities and for training reasons, like healthy nuts such as almonds, Brazil nuts, Filberts, pecans, etc., and then a little fresh fruit (lots of sugar in fruit, so it's more of a treat).
****NEVER ever pull out any of your bird's feathers!!! First of all, it hurts him a great deal and will only make him angry, scared of you, you'll lose his trust, and will do absolutely no good in getting his feathers to grow back if you don't know why they aren't growing to begin with, and if you don't know what you're doing...And what you pulled out is called a "blood feather", you're extremely lucky that it wasn't a large blood-feather that continued to bleed, as your bird can literally bleed to death very quickly if you happen to pull a large blood-feather out. So don't do that again. Ever.
***It sounds to me like your bird needs to see a Certified Avian Vet or Avian Specialist Vet that has a lot of experience with Feather Destructive Diseases, as well as Avian Diseases in-general, as like Christa already mentioned, there are some extremely serious diseases that parrots can suffer from that would cause his feathers to not grow, but also to eventually start falling out. And unfortunately, some of these diseases are actually fatal. So you need to get him to an experience Avian Vet for complete blood-work and some cultures, as this will tell the Vet whether or not your bird is malnourished due to a bad diet, whether or not he's deficient in certain vitamins or minerals, and whether or not her is suffering from an illness or disease that may be more serious. There's no way to know without diagnostic testing, but you need to get it done ASAP, as some of the diseases we're talking about need to be caught extremely early in order to have any chance of treating them.
In the meantime, can you tell us exactly what you've been feeding him daily since you brought him home, I'm assuming when he was just a baby? I'm sorry I don't know what "Macaw Nuts" are, maybe someone else here will...but if you've not been feeding him pellets and fresh veggies every day, then chances are that he's suffering from some malnourishment that is causing his feather issues.
