Breakthrough after giving up walking

Our puppy is now a year and 1 month, around the 8 month mark I decided I was done walking him.

He is a border collie/ german shepard/ australian shepard/ husky mutt so very high strung, alert, and impulsively wanting to give chase just by nature. Plus when he was around 4 months old we were attacked by a Shiba with an owner who wasnt paying attention (he was between my legs so it didn't get to him but he had a close up view as I stuck my arm in the way of the dogs mouth when the Shiba started really aggressively trying to bite him)

His reactivity was getting worse and worse no matter what I seemed to try. I did a ton of counter conditioning with high value treats when he'd see a dog on his walk but his threshold for how far away that dog could be before he'd start literally flinging his body towards it (jumping, twisting, barking, whining) kept getting farther.

At his absolute worst we saw a dog from a football fields worth away and he immediately reacted and lunged forward causing me to really badly roll the ankle that I had already sprained walking him that week. We went home, I cried, said no more, and was on crutches for nearly 2 weeks.

So we stopped walking him entirely. Focusing mainly on high energy playtime in our fenced backyard as well as obedience and crate training. The only other dogs he saw were my family's two spayed adult female dogs in supervised playtime. Every few weeks I'd leash him and take him just out in front of our house for training to see if anything had changed.

Well yesterday I took him out front on a long lead and a collar, looped the end of the lead around my wrist while I was cleaning out my car and gave him treats for checking in on me in between his duty of shredding a cardboard box to fix into the recycling bin (lol).

3 separate dogs were walked past our house, only 10 feet or so away from where we were standing. I did have to do some management when. we saw them because he would start walking towards them but

he came back when I called, he took treats, he didn't bark, didn't lunge, he was excited but calmed down within a few minutes each time, he even sat down beside me when he saw the 2nd one and looked at me expectantly for a treat.

Its like a switch flipped in his brain.

We are still going to take it slow and easy because I don't want to risk stressing him out and ruining the growth he has had but I just wanted to post this in case anyone else with a very reactive puppy is having the same thoughts I was of "Oh god I hate this dog, have I made a horrible mistake".

Anyway I love him and I'm really proud of him. In another year or so after he is fully grown I want to start training him for bike joring on private trails so this bodes really well for me not dying just because my dog saw a squirrel or coyote lol.