Some things cannot be fixed. I urge you to get a qualified behaviorist (veterinary) to evaluate him. If he is truly unstable, rehoming him is not fair to him or the new home.
Oh no! Poor Quinn. The past few months have been rocky for him. You really are an amazing person for all you have done and continue to do for him. I'm sure he knows that he is loved now. Sending happy thoughts and hugs to both of you!
I wish I could take credit for this post, but it's just information that BRAT shares with folks who are either fostering or adoption a basenji.
BRAT really does try to cover the bases with inof re new dogs and owners.