How do I recover my email account and important emails?

I signed into my old account to delete it because I don't use it anymore which was *** Email address is removed for privacy ***. I followed the process to delete it and after it was deleted it went to the sign in page and I assumed it was deleted. After that I logged into my current account which is *** Email address is removed for privacy *** and it was like a new account and all my important emails that I kept was deleted. How is this possible when I know that the account I deleted was my old one and not my current one? I don't know how it could delete my current account when I actually deleted my old one and made sure of it before I closed it. This is stressing me out and I need my important emails back from *** Email address is removed for privacy ***. Please help me ASAP. My important emails were kept in my "Keeps" folder and some in my inbox.