Question about a stray

[Mahealani770]

Hello everyone, I need some help, please. I have taken in a stray pomeranian. He is male and is not neutered. I have had him for 3 days and I'm ready to give him back! He barks excessively when we're not home or when we're out of his sight. He also goes potty all over the apartment and tears up my plants when he's left alone. I tried crating him while we were gone for just a few hours and he went potty inside his crate. It was so bad that we had to throw his blanket away. On top of that, he barked the whole time we were gone. Is it separation anxiety? Can all this be fixed? We feel like we're trapped in our apartment with this dog because he just can't be left alone. Help!!!