I'm sorry that your question wasn't answered in a timely manner. We don't have many avian vets on this site. Head trauma in birds is most often treated by not doing; in other words, handling is kept to a minimum and the bird is placed in a dimly lit, quiet, warm (29.4C) area until it remisses from the shock of such trauma. It mustn't be allowed to fly about until it has completely stabilized.
It's not unusual for the stress of rehoming to result in inappetence. Because nutritional imbalances are a common cause of illness in our pet birds. What has Gloi's diet consisted of, please? Seeds should compose less than 20% of his diet. A diet of mainly seed and nuts has excessive fat, carbohydrates, and phosphorus; marginal protein; adequate vitamin E, and are deficient in amino acids, calcium, available phosphorus, sodium, manganese, zinc, iron, vitamins A, D3 (necessary for efficient absorption of calcium), K, and B12, riboflavin, pantothenic acid, choline, and available niacin. Ideally, a balanced pelleted diet such as can be found here: www.harrisonsbirdfoods.com or here: www.lafeber.com/pet-birds should be fed as well as hard boiled egg yolk, pancakes and cornbread, the tops of fresh greens, dairy products such as yogurt and cheese, fresh fruits such as apples, pears, melon, kiwi, and berries, vegetables such as broccoli, carrots, beets, asparagus, cabbage, sweet potato, and squash, and even tiny pieces of meat.
(Curiously, I just received photos from friends currently visiting your island. Wow!) Please respond with further questions or concerns if you wish.