My Xbox won't let me in because my old email suddenly doesn't exist. What do I do?

Question

I tried getting on my xbox again after 4 months or so, and my xbox account can't be signed into because the original outlook email doesn't exist. I've tried to change the email to my current one, but I can't get past the "we're changing things" page. I've tried everything. This account is about 6 years old and I don't want to lose all the things I have on it. Nothing seems to work, and I really don't want to make a new account. Please help.