From what i went through with my dog, it sounds like yours just isnt exercised enough. Pit bulls need like 45mins-an hour walk every day. sometimes more depending on the dog. We thought ours had separation anxiety and we just lengthened his walks and he’s fine now. Running in the backyard doesnt work, they mentally need to get out of the house, kind of like if you stayed home all the time you’d get cabin fever. Also i agree with the person above: kongs are a godsend.