Too fast too soon.
With a dog as timid as Moose sounds like he is, dominance is enforced an entirely different way, at an entirely different pace(depending on dog, but still FAR slower than any other dog). Also, HOW did you ask for/enforce the wait? Don't allow him to become TOO clingy--you do not want to create separation anxiety. Allow him to come to you for comfort, but don't try to make him come to you for comfort. He can come to you when he is uncertain, but you absolutely cannot reassure him in any way--JUST BE THERE. That's it. Nothing more, nothing else. Don't coo to him. Don't love all over him. Don't talk in a soothing voice. Just be there, allow him to be as close to you as he wishes, and don't act any differently.
Not to burst your bubble....but he will most likely never be an independant normal dog. Dogs as timid as Moose sounds like he is, ESPECIALLY since he had NO contact in the crucial socialization period, are going to be timid for life. Now don't let your heart break--they can be helped. They cannot be fixed. As the owner of an INCREDIBLY timid dog, I know where you're at. Z, now four years old, is just now getting to a point where he is comfortable greeting people on his own. Although, he is STILL not happy with strangers. In time, he will become more comfortable, and more confident, but he will never be the outgoing social butterfly that my people-loving female is. Period. Dogs like Zeke and Moose are not "fixable." They can certainly improve, they can lead happy lives, and they can learn that the world is a safe place. But they will never be like a normal outgoing dog.
Given Moose's history, your absolute best bet for both him and you to be happy is to find a professional(this DOES NOT mean a Petsmart trainer. No offense Fickla!!! You're an exception. This means a BEHAVIORIST). Dogs of this type are one of the hardest to work with, and the easiest to force into regression(as you've seen). You will absolutely need help. I'll get a list of books together for you that I've referred to many times and add it to this post. Best of luck, and again...don't take what I've said the wrong way. Moose isn't hopeless by any means--but don't think that you can mold him into a happy, outgoing dog. He is still very young, however, and will likely improve much more than an adult dog of his history would--with the right training and care.
Zeke has been very very timid all of his life. As a pup, he would not approach people at all. He would cower and refuse to move. With dogs, of any size or temperament, he would flatten himself to the ground and urinate. He had no history of abuse whatsoever. Just lack of socialization, when I got him at 3 months. I have been working with him since the day I brought him home, and recently I posted about some GIANT breakthroughs for him(A BRAVE Moment in the Life of Zeke). If you find the right help, these are breakthroughs that will be huge to you too, when they come. It is very easy for these dogs to develop separation anxiety---they go from a world of incredible fear, and enter a world of acceptance and safety. For Zeke, he was showing early signs of separation anxiety in the first week that he was with me. I mistakingly thought it was just the change and the anxiety of his radical change in home, and assumed it would pass as he adjusted to his new home and life. I was very wrong and ended up devoting a lot of time to getting past his SA. To this day you can still see remnants of it at times. He is certainly a velcro dog, and if he is in a "scary" place or situation, he is glued to my leg and panting very heavily. This is an improvement--he used to have to crawl in my lap(a 60 lb dog) and be as close to me as physically possible. This had nothing to do with dominance, and everything to do with being terrified of being too far away from me. The more he improves, the more distance I require from him so he can learn that being away from me is okay. That's another thing---be incredibly picky about which behaviorist you choose, if you so choose to use one(I very highly recommend it). If you choose someone who isn't purely positive, they are likely to mistake some things as dominant moves, when they may not be. (For instance, Z crowding my space...it's not him trying to dominate me, that's him panicking and going to his safe place. I don't pet or coddle him, I just allow him to come to me. The braver he gets, the further away his safe place is--no more crowding, because he can handle it further away from me.) So choose a 100% positive behaviorist with experience in timid/abused dogs.
Whatever you do, do not baby him. You will certainly make him worse. For now, do the easy, NON-intimidating things to let him know you're in charge---teach him to sit, and have him sit before eating(if he is not food aggressive--if he is, you'll need to tackle this first); do not free feed at all. Do some research on the NILIF methods. This means "Nothing In Life is Free." There are many non-intimidating ways to use this method that will teach any dog who is in charge, without ever so much as raising your voice to them. For now, you could try teaching him to target. He could earn his meals solely by targetting. This would be great, because he would learn that YOU are his provider, and that you are safe. If you have a target stick or can make a target stick, this will be your godsend for a long time with Moose. Teach him to target this, and use his meals as rewards. Each piece of kibble is earned by touching the target with nose or paw or chin or whatever you want to teach.
Hope this helps, and good luck!!!