Signing in to xbox live

I am having problems signing into xbox live. I sign in with email and password then it prompts with - Already on your account- with an old email address. I set up a different email address and I then get -Thanks! You added this earlier, but we can't use it until you verify it at accounts live. It won't let me verify it and no matter what I try I cannot sign in. I have not had this problem before and am getting very frustrated -please help!!!!
Thanks.....