I find one of the biggest hurdles to get over when helping dog owners modify unwanted behaviours in their dog, is convincing many of them not to project their own current emotional state onto their dog, especially when trying to modify their dogs behaviour.
A dog isn't sad because we are creating new rules and boundaries. In most cases it's the dogs owner that is feeling sad because they are not having their own emotional needs fulfilled by their dog as they were probably used to in the past. The dogs owner is simply projecting their own current emotional state of loss onto their dog, due to their own perceived lack of (previous) conditioned emotional fulfilment, due to the suggested new rules and boundaries to follow to help their dog. The dog will certainly adapt to new rules and boundaries just fine, and in actual fact will thrive with them, however, only if the owner is willing to not allow their own emotions to control and therefore influence their behaviour and relationship with their dog.
What you are seeing and feeling from your dog, is usually how you are feeling, not how your dog is feeling.
Society has become so conditioned to overwhelm dogs with heaps of affection, and in most cases this is more about fulfilling the owners emotional needs, than what is best for the dog.
There needs to be a balance of rules and boundaries, and offering affection. Affection is a way of rewarding and reinforcing behaviours you want, not simply to get affection returned from your dog. In most cases, many behavioural issues are created by the owner due to the overwhelming need or desire to receive affection (emotional fulfilment) from their dog.
I have attended many homes of dog owners that couldn't see how their strong (and unrealistic) desire for affection from their dog was not only contributing to issues like anxiety and hyper-arousal in their dog, which was then causing so many behavioural issues, but that their need for copious amounts of affection was also continually feeding these states in their dog. Many of these dog owners thought their dog wanted to show affection to them because their dog loved them so much, when in actual fact they were doing no more than making them self a high value recourse to their dog. No different to a dog that has a strong desire for food, a bone or toy. and feels the need to control and even guard it. This isn't a dog that "loves" the food, bone or toy, it just has a higher value than other things in the dogs environment that it wants to maintain control of.
I have lost count how many homes I have visited over the years whereby dogs were resource guarding their owner/s, and the number one reason for this aggressive behaviour? Copious amounts of affection from the dogs owner! Even many cases of dogs with insecurity and unnatural and/or unrealistic fears, can in most cases also be attributed to giving dogs way too much affection. I have come across many, many dog owners over the years that weren't even willing to modify their own behaviour to help their dog due the emotional fulfilment they felt they lost or would lose from their relationship with their dog. This loss was way too much for them to bare. The amount of stress they were willing to accept from their dogs unwanted behaviours was insignificant in regards to the amount of emotional fulfilment they feared they would lose by modifying their own belief system and therefore their relationship with their dog. The loss of this "false" sense of loving affection from their dog was way too much to accept.
It is so important not only for our own emotional health, but more importantly for our dogs, that we maintain a sense of emotional balance in regards to our relationship with our dog. Try not to condition yourself to feel that a dog is there to just fulfil your own emotional needs, that is putting way to much of a burden onto your dog, and therefore, in many cases, causing your dog a level of stress that your dog should not have to deal with. Certainly, love your dog, and yes of course even offer affection, however, we need to be so careful that our need and desire for emotional fulfilment from our dog doesn't override our sense of duty towards our dog, ensuring its overall psychological and physical well-being.