Adopted a dog who can’t be trusted around anyone except me without a muzzle. They did not fully disclose His history. He’s 75 lbs and I can’t handle him. They won’t take him back, what do I do?

That is absolutely untrue. They will take the dog back. As far as the history, they dont know the history of the dogs that come through for the most part. You can't expect them to know everything about a dog. They WILL take him back

All dogs go through an evaluation process. Behavior is assessed as well as can be done in a short session, as many of these animals are transferred in from other shelters or found as strays. They will absolutely take him back. Their focus is well being of the animal and overall safety. Your other option would be to invest in some training. Growing the relationship and teaching some basic obedience is always a good idea.

Call and talk to the rescue people there. They might be able to help. I'm sorry that happened. Happened to me a few years ago, similar from a different facility.