Ok, so I guess I can't help face to face. I could by phone call if you wish. Your Westie is the key here. Do you take both out for walks at the same time? Do you have a small breed dogpark?
Your poor dog needs to feel like a dog again. Would you consider going to training school with the pup? Being around others may help tremendously.
Also, since the dog has confidence issues DO NOT CODDLE the dog. This is the worst thing to do and infact it has the opposite effect.
Who knows what this poor soul went through in life. Some things can be corrected and others not so.