Mickey

So for those of you who do not already know, we recently rescued a 6 year old English Springer Spaniel who we have named Mickey. My yearning for a dog started around the same time I was diagnosed with PCOS. I just felt a void, I wanted(want) another child and knew it was going to take time, I was concerned I would drive myself insane before the time actually came and convinced Mike to let me get a dog. That was one of those times I pushed him into something I don't think he truly wanted. And now I am concerned I am seeing the repercussions of my actions. 
When we were first approved through the rescue Mid-Atlantic English Springer Spaniel Rescue (MAESSR for short) we were put on a waiting list. Because we were very specific about a few things, child savvy dog, good with other dogs and cats, we were non-specific about other things, age, color, sex, size. The rescue also warned us it may take a little longer because of our needs. Shortly before Christmas we were offered a dog, his name at the time was Cody and every volunteer that had met him had nothing but wonderful things to say about him. he was reportedly excellent with children, other dogs and cats. We had found our match!! Because of a pre-arranged trip planned for the beginning of January we arranged pick-up for the day after we got home, January 7th.
I was so excited the day I drove to get him I kept feeling like I was going to cry! Meeting him was wonderful, it wasn't until I sat down to sign the papers that I learned the baggage we were taking on. He was overdue to be groomed by what looked like several weeks, I was initially fine with this but after writing my $225 check I thought, why couldn't they have taken care of this BEFORE we came to adopt him. The foster mom then handed over his medication which she said was for a thyroid condition. I'm thinking, no problem, we can bond over it!
When I got home I immediately called Petsmart to get him in to be groomed the following day, and started researching his medication. I come to find out this is actually an Anti-Anxiety med. I was completely shocked, not only had the rescue failed to mention he was on meds for anxiety I had no clue what he was on them for. Does he get aggressive? Is he destructive? What can I look forward to if I decide to wean him off these meds? I e-mailed the foster mom that day to get more information, three days later she finally came back with a very vague and obnoxious answer. "When we took him to the vet for the first time he was just so anxious I couldn't bear to see him that way." Great, thank you for all the details. The woman then failed to deposit the check I wrote her for three weeks, even after I called and e-mailed her multiple times. Decided to keep him on the meds, which they gave me a fair supply of, until we visited our vet for the first time.
What turned out to be a case of kennel cough took us to the vet sooner then planned. She was very helpful, explaining that Springers have a tendency to be an anxious breed, especially when there living situations change, much like his had in the last few months. $115 later, we were leaving the vet with meds for Kennel Cough and some information about natural ways to treat anxiety.
A few weeks later, we felt his kennel cough had mostly recovered and we were ready to try him off the anxiety meds. First few days were fine, probably some still left in his system. About a week after taking him off his meds we started to notice a change in behavior, he started to become very attached to me, not getting out of bed in the morning until I did, refusing to eat any meals unless I was sitting in the room with him, much more growling at Molly and Mike. A couple times got to the point that he needed a "time-out" in his crate for growling at one of them. He also continuously licks things and will bark at just about any noise.
Initially I wasn't noticing this as a problem, yes, he barks. Ok, so sometimes he isn't very tolerant of Molly. It finally took me seeing him in action against Mike to realize there was an issue that needed to be addressed. I started him back on his meds today while I try to figure out what to do. I really don't like the idea of him being drugged. But I also don't know what it feels like for him to constantly be so anxious. And of course I don't feel like Mike has been much help, I tried to explain to him that Mickey still doesn't know him very well yet and it is part of his anxiety towards him. Mike works and goes to school the majority of the day, on weekdays we only see him for a few hours in the evening after he is done at work. And he still has to work every other weekend. So to Mickey, he is a stranger. Especially since I do everything for him, taking him on several walks a day, letting him outside to go to the bathroom, feeding him meals, giving him baths. Why is it my fault the dog likes me better?
But this was not meant to be my dog, it was meant to be our family dog. How are we supposed to have a family dog if that dog only likes one member of the family? Should I just get over thinking about him being drugged and just do what helps him?