I need some help

Ok Bear is 7, first off please do not judge me for getting a dog off kiijjii as its the past.

When I first got him I was told he was 2 and good with kids trained etc well first off he is 7 and not trained or good with kids but is awesome with other dogs his own size.

I have got him trained now to do his business on paper and outside which is how I prefer it as I do have a child and live in an apartment and don't want to leave her alone for evening walks after dark as she would freak if she woke and me be gone, he is fine on the leash so long as he doesn't see a kid (which is really hard not to do when my window faces a school yard) and if he does he runs between my legs.

My vet said he was most likely abused and she suggested another dog as companionship for him.

anyways onto the issue

Bears will bark and growl in a very aggressive manner any time my child enters the room I am in if he is there which is unfair to my child. She is not scared of him by any means and he does stop after I tell him no,stop, go lay down about 4 times.
He does not do this if I am not in the room though

My child has never done anything to scare this dog or anything

things I have tried

making DD be the only one to feed and water him so he would "need" her for something and trust her nope unless she was carrying food he still barked and growled

walking same thing except I had to literally carry him out the apartment door put him down and close it or he would not leave with just her otherwise he walked fine for her so long as I am not in sight.

I really don't get it help me please, though I get the idea the vet gave about another dog as I had my friends shih-tzu here one day and the behavior stopped I do worry that possibly another dog would pick up his behavior instead of correct it