You're not by any means the first person that has been locked out of their Facebook account. In order to deal with such occurrences Facebook has created a webpage called Disabled Accounts.
1. Go to the Facebook Desktop Help webpage.
2. If you can't access your Facebook account you should see pictures on the Facebook Desktop Help webpage that look like the screenshot below. You have to be logged out of Facebook in order to see this picture. Click the light brown button that has: Get Info About Disabled Accounts underneath it.
3. This will take you to another Facebook webpage called Disabled Accounts. This webpage has a lot of information about how to re-enable a disabled Facebook account. Look for the link on this webpage called My personal Facebook account is disabled. Click on the arrow to the left of where it says My personal Facebook account is disabled to unfold the text beneath it so you can read it.
4. In the unfolded text beneath the My personal Facebook account is disabled heading there is another link that may be of interest to you called submit an appeal. If you think your account was disabled by mistake you can click on this link to submit an appeal. Submitting an appeal is something that you can do in case you think that your problem is being handled incorrectly by computers, and you want someone to give personal attention to re-enabling your disabled account.