Having worked with reactive dogs and owners and being the owner of a reactive dog that changed my life I hear you OP.
I strongly believe that owners do go through a period of grieving and I witness this with owners I have contact with.
They tend to start off with anger, why does my dog behave like this, what has happened to my dog
Then often "oh it will be ok I can sort this out "stage
Then to "if only he behaved like other dogs"
Doubt "There is no way I am the best owner for this dog he needs someone better than me"
Eventually getting to the "yep my dog is special and I need to work with him to make his life great" - this is when the difference is made
Owners of reactive dogs get a really hard time by the public. People who have only just meet their dog have "the answer" to the dogs problems. " you should have socialised him when he was young, he will be better off lead, just let my dog sort him out, you need to show him boundaries and who is boss!"
None of the above is true
. Reactive dog owners know their dogs better than anyone.
What I see when I see a reactive dog owner is someone who cares, someone who has made major changes to their lives and their dogs live, may have spent pounds on training, will have spent hours and hours looking for solutions, hours looking at websites reading books etc. Reactive owners are dedicated, caring and AMAZING people!
What has helped some of my clients is concentrating on what your dog can do and really exploiting this.
My first reactive dog (I now actively choose to get reactive dogs but that is another thread!) would attack any dog he saw, heard, or smelt. If he could not get to it he would attack what ever was near him instead. Good points were he was pretty consistent so very easy to know what was going to happen
. However he was fab and I mean fab at agility. By concentrating on what he was good at and just avoiding what he was bad at we made huge progress. Eventually we were able to complete in big competitions and he and I loved each others company.
So I would strongly recommend you find a qualified behaviourist and trainer (they will do different things) and look at what makes your dog happy , what makes you happy and really concentrate on that. Avoid triggers if you can (this can be hard to work out but behaviourist should help with this)
Maybe change your mindset from wanting to change your dog to change on working on what he is good at.
Op re reassurance yes some dogs can totally transformed some can learn more resilience but may not be as bombproof as other dogs. Whatever the outcome with your dog it is not a judgement of how you are as an owner. I do strongly recommend professional help, it can speed things up, give you a realistic plan to work through and someone to mentor you on those tough days.
Without being too gushy for MN all reactive dog owners have my huge respect and be proud of the homes you are giving to your dogs - you are the best[ smile]