i found a lot of help with training books and a show called the dog whispered, not sure if you have natl geographic channel where you are, but this guy is good-you have to watch it a few times to get what he does, but basically -retraining yourself-and your dog.
i didnt realize it, but my dog thought she was the leader of the pack and i was allowing it...
ps-separation anxiety can sometimes be helped with a cage-type kennel -where they can still see out-and a kong type toy filled with peanut butter or some other yummy treat (your local petsmart or someplace has these chewing toys that are awesome for those lonely chewers)
Good luck! there's a ton of information in these threads i've found helpful too.
welcome!