Aggression issues

[Terrie]

My 6 month old GSD has got serious aggression
Issues. He is a working dog, both his parents
Are police dogs. He was given raw meat
As food ( which I immediately weened him off)
He is biting, not so much my partner because
She halls back, but me, yesterday I fed him and when I
Went to go to the living room, I patted his behind, he
Turned around, growled and lunged and bit me hard. Let's just say
In a sensitive area where if it was someone
elses dog, he would be put to sleep. Now I don't
Trust him and he drew blood from me.
He has gone to training classes and the trainer
Who's also the breeder is blaming us for not
Keeping up with the training. He is walked
Every day for one - 2 hours. He has his own
Pool and we play with him all the time. Any
Suggestions? I need help because next bite
He's out of here.