separation anxiety and crate training

Question
goesI have a 3 year old, maltese-yorkie dog who uses the bathroom in his crate.  The crate is not too big, only large enough for him to turn around in and lay in.  He also chews his paws, whines, barks, and pants excessively.  I took him to "Man's Best Friend" and they worked with him for 2 weeks with crate training and obedience training.  He behaved for them and he won't do the same for me.  I had him crated until he was one, while I was in college.  When he was in the crate back then, he only urinated and barked excessively.  My college roommates used to hit him and sprayed him with water when he barked.  When they started kicking him, I moved back home with my parents.  While he lived at my parents' house (with me) he had free roam around the house.  They were able to take him out when he needed to go, but he still lifted his leg when he had to urinate.  I purchased my first house less than a year ago and he is urinating and lifting his leg on furniture and then sneaking down stairs to poop.  We are trying to keep him in the crate while we aren't home and for a little bit of time when we are home.  We've tried everything!!!  He is the sweetest dog when I am around and always wants to be next to me.  At first, I thought he wanted me to bathe him, for more attention, after he pooped in the crate, so I started spraying him down with the hose.  Please help!!!  I've tried everything...bark collars, $2000 dog training sessions, anti-anxiety spray, potty pads, putting him in the bathroom to give him a little more room, putting his nose in it, spanking the daylights out of him, being sweet to him even after he poops, etc.  I do believe in positive reinforcement and praise when it's deserved.  We make sure to praise him when he goes to the bathroom outside.  He knows that he is doing wrong and doesn't have a problem holding it when he wants to. At night, he sleeps in the bed with us and holds it the whole time and rarely even whines in the morning for me to take him out. It appears to be more of an anxiety issue than a physical one.  Please help!!!  We are desperate!!!!!!  

Answer
Emily, I apologize for the tardy reply. I work for a CPA and this time of year is horribly busy for me. When exactly does he potty in his crate after you put him in it? Is it immediate, or after you've left the room? How does he behave in the crate if you remain home? Is he neutered? Lifting his leg is marking behavior, not a housebreaking issue. Pooping in the house, however, is a housebreaking issue. I would recommend that you keep him on a leash whenever he's out of the crate, and either just let him drag it around and use baby gates to keep him confined to the room you're in, or keep him attached to you so you can immediately take him out as soon as he begins showing signs that he is getting ready to go. Putting his nose in it and spanking him are not the appropriate ways of dealing with the issue. I recommend that you stop doing that now.

Do you give him any bedding in the crate? If so, try removing it. Sometimes dogs will go to the bathroom in their crate if they have bedding, but when you remove it, they stop.

Have you tried the DAP diffuser plug-in? Have you spoken with the vet about his anxiety?