Rescue terrier aggression

Question
Hope you can help.  We adopted a male terrier/sheltie/other mix from a rescue about 3 months ago.  He is now about 6 months old.  He has had issues from the beginning.  He is incredibly cute, but he has had food resource issues, is territorial about his toys, and bites.  We are a family of four with two children, ages 4 and 7.  He tried to bite the kids in the face early on, (didn't break the skin, but still concerning) but after some scolding he has not done this again.  He is fine with my husband, but I seem to be the problem.  When I scold him for jumping, barking, or anything else, he becomes aggressive with me.  He will snap his teeth at me, and if I try to grab his collar, he will bite at me.  I have taken him to obedience school and to a private trainer.  His food resource issues are better.  Some things work for a little while, and then he reverts to his old ways.  I can't leave the kids alone with him or let him out of his cage when anyone visits.  Honestly, I would like to return him to the rescue, but I fear for his fate and for what message this sends to the kids about working through a problem.  We are not enjoying this dog.  Help!

Answer
I am not opposed to getting rid of a dog that does not
work in your life. I fear for your safety and the kids safety.
My friend rescued a poodle and it bit her daughter. Now
she looks at her daughters scar on her face everyday. It's not
teaching the kids to not to work through a problem...it's a
matter of safety.
Good luck