His name is Fritzyie and he is one year old.He is constantly scratching himself and stoppes chirping and singing.

I'm sorry to hear about this with Fritzie. Pruritis (itchiness) can be the result of lice and mites, malnutrition, dermatitis (fungal, bacterial), polyfolliculosis (uncommon in canaries), feather inclusion cysts (common in canaries), and allergic dermatitis (conjectured).  It would be best that an avian vet (www.aav.org) examines Fritzie hands-on but if that isn't possible, you can treat parasites presumptively with over the counter Scatt (moxidectin) and you can improve Fritzie's diet.

What has Fritzie's diet consisted of, please?

Seeds should comprise 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 - yes, these low lactose foods are safe, 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. Here are some tricks in transitioning him to a formulated diet: https://www.harrisonsbirdfoods.com/using-our-foods/diet-conversion/ and click on “Feeding Harrison's”.

Please respond with further questions or concerns if you wish.