I requested to change my name and now when I enter it asks me to add a document that shows my name, I don’t want to add a document because it shows my real name and it doesn’t let me proceed because of it, can I at least cancel my request and log in with my old name?
That's probably a question for facebook support rather than an internet marketing forum. Now if you want to know how to promote your business using facebook, we can help with that!
You can't access your Facebook account now even if you upload your document to FB. Because you have changed your name and if the current Facebook Name and Document Name will match then you can be able to access your Facebook profile otherwise you can't and there is no support to fix this.
These all things you should know before changing the name as well. If you request and upload a document to Facebook, It's important to have the same name on the document. Otherwise, they will consider it fake/spam. I think you will lose your account.