Sena, one day you'll look back on this and laugh..
I adopted an 9-month kelpie who'd been raised in a tiny flat.. he was never walked or played with, didn't know what a ball was. Wouldn't go outside by himself, even though we left the door open all day and encouraged him, put his food outside.. Daughter and I had to coax him out to play - then teach him how to play. He had severe separation anxiety due to being left in the flat all day alone and ruined four or five pairs of curtains (the windows were his focus, which was a worry) and couldn't leave him in the yard for even a moment without him vaulting our 6-foot fences. Once he was confident to go outside alone, he figured out how to work the door handles by himself and would sneak out to follow Daughter to school.. He tracked her right to her class one day and bounded in, sat at her side, then dropped and stayed, like a good dog!

He was popular with the other kids, if not the teacher.. He also followed me to the supermarket a few times, trotting down the canned goods aisle all pleased with himself .. "there you are!"
I used to walk in and out of the house a lot... Kelpies are incredibly smart and quick to pick things up (and then innovate! on those things.. gotta watch that.. like the door handles.. ) so it didn't take him long to work out that he was no longer going to be left alone for 12 hrs a day.. we were always going to come home/come back to him. He had his own version of pacing which was this creepy fixation with staring out of the windows. He'd stand there all day if we let him.. shaking and whining. Breaking the fixation was the hardest thing.. until we figured out he liked the TV a lot, and would call him over to watch it with us every time we caught him staring.. then it was ball games. Anything to break that habit, which seemed some sort of 'key' to his anxiety habits - once we weaned him off that, suddenly there no more ruined curtains. Maybe the pooing/peeing and pacing are linked like that..stop the pacing, the pooing may follow!
Lots of his 'play' time with us was taken up by basic training (he didn't know anything at first) but Daughter taught him many tricks on top of that and he couldn't get enough of that kind of 'play' - it really was win/win. He had fun, we got a dog with good manners. We eventually replaced voice commands with hands signals so he'd pay closer attention to us and we weren't shouting across the yard - this worked wonderfully.
We worked so hard to undo all the damage - and then had to leave our house, had trouble finding a new place and in the end couldn't take him with us. He was rehomed with a deaf person who was eager for a companion dog. Being an intense working breed, he loved having little 'jobs' to do (he carried my peg basket while I did the laundry, lol!) so being retrained a 'hearing dog' was right up his alley.
To this day we miss him horribly.. all those months and months of problems seem like nothing compared to what he gave us, all that love and eagerness to work us out, as we tried to work him out.. and all the ruined curtains were worth it.
Sorry for the ramble, but we had such great success with our dog, I felt I had to share.
Good luck with this little guy. I'll be reading his progress..