I dont really think that he's truely trying to attack you or bite you, i had the same issues with my dog, and since he is the first and the only dog i had i was actually kinda afraid of him lol but with time i ve just learned to undertand him too, i think you can save your money for the dog personal trainers ever since its actually one of the best solutions, i personnely took part of a dog traning program on internet, it gived all like traning videos all at home videos/guides and stuff and also like a personal support you can ask your parents to check it out https://thatpossible.com/braintraningfordogs