While dogs do grieve it should not go on for as long as it has and I would more suspect a health issue.
Since this is sudden I would have him re-evaluated by your vet as Labs are prone to hypothyroidism and this can cause the behaviors you are seeing. If there is a thyroid problem it can easily be fixed with daily meds, and the meds are not that expensive. A thyroid problem can cause aggression and cause a dog to be fearful.
If he is nipping people that come into your home until you can get the dog evaluated by your vet you may want to hook a tether that you can access and tie the dog to when someone comes to the door. I would also suggest you find a behaviorist in your area that can come in and see the dog first hand.
Thank you! He was neutured when he was 18 months because of his dominance and has never been the same since. He was very dependant on his elder mate who was 13.1/2. He is a real baby, needs to be babied to eat, but he also has a nasty agressive part to him, although he is as gentle as a kitten inside the house. I do not baby him, other than to try to get him to eat.People say leave him and he will eat when he is ready but when his mate died he would not even drink anything and I let it go on for 4 days before Istarted handfeeding him to get him to eat and survive.Now he eats but it has to be alongside me at the table. He seems threatened when outside, unless he can be right alongside others. I will call my vet and get this seen to. I have long since thought he was too docile and thought it may have been a testosterone problem since he was done.
Thank you very much!
He has an appt for a blood test on Tuesday, results back Friday I rarely hit him as other behaviour methods are more my line. Yesterday I spent putting him through his paces so he has no doubt who is boss. He is eager to please. I don't want him to have anything wrong with him, but I don't like dogs who bite and I have to know why and if it is what you said, which seems a distinct possiblity as he hides when it is windy and won't eat or drink, loud noises make him skitty. He is deaf in one ear but he should not bite. My other dog is completely laid back as was his predescesor.
Have a great weekend and thank you for your insight!