@ivyt85 I have a nearly 7 year old reactive cross with separation anxiety, who I've had since she was a puppy. Her reactivity is in her genes (her dad was reactive) and I was young and naive when I got her.
We have had trainers in, and it's always 2 steps forward and 3 steps back (mainly due to other people triggering her), so we have ended up just adapting our lives around her. I changed jobs and now work from home, and we bought our first house with specifications that would make life easier for her. We don't go out together unless a close relative can come and stay with her, which is rare, and we walk her really late at night and book dog fields for her.
I'm saying this to let you know that I FULLY understand. My dog is amazing 95% of the time, but that 5% can run your life. The fact that I have been able to make these changes for her is sheer luck, and if I couldn't, I might be in the same situation as you.
We thought about rehoming her when she was younger, but we knew nobody would take her, and the upheaval of her life would make things worse, so we just powered through.
Again, we are so lucky that we can change our lives to suit her, but it is a huge thing to do and not everybody can.
You know your dog and your situation, and you know what is right for him. I fully support your decision, and I know a lot of these comments are judgemental, but unless they have been through it, and/or are willing to take him personally, they are just making noise.
I'm sorry you're going through this, but it sounds like you've done everything you can for him, so try not to take those comments to heart.