Do something fun with your dog every day. Remind him (and you!) how much you appreciate him. Especially if he frustrates you, try to make up for it by having a positive interaction. If he isn't doing well in training, go for a walk, play some frisbee, hide treats for him. Remember that he is doing his best and while we as humans have many ways to find appreciation from different areas in life, he (hopefully) gets most of his life satisfaction from being your friend. Be his friend every day!