Sounds like your stress and anxiety are being transfered to your dog. You come home stressed and tired, and that is a weak state that your dog picks up on right away. All the treats, toys, and love in the world won't calm him down. They will just reward that anxious behavior and state of mind. Some simple things you can do at home without a trainer are just being calm and not rewarding anxiety from Coco. When he is whining, circling, panting, or just being tense, do NOT pet him and try to get him to calm down. That is only rewarding and nurturing the bad behavior you are trying to get rid of. Re-evaluate what state of mind you are in at that moment, and get your stress and anxiety under control. Just be calm and collected. Wait for him to become totally relaxed. Don't talk to him or say things like "It's ok, Coco, calm down" because that nurtures that anxiety as well. Just be quiet and wait to reward him until he is calm and submissive. Then you can give all the affection in the world because you are nurturing the state of mind that you really want.
Also, when you take him out for walks, wait until he is completely calm before even putting the leash on. It's good that he is behind you, but unless he is calm, you are not accomplishing your goal. Be the calm cool center of the universe and your dog will respond in a completely different manner.