I don't think there is an easy way to know which email address you used, afaik. But if you have an idea on which email address it could be. You could try to retrieve your password using the options below. Once you have the right password, you can try this to unlock your phone.
You can open Google on your pc and try to log in there. Try the password recovery options on the site. Passwords are made to be secure, so trying to recover them is something that was made hard on purpose. You don't want other people to be able to recover your password.
If you have set a main recovery email address on Google. You can use this option to recover your password. But this will probably be clear if you push the "Can't access your account?" link on the site.
Also a tip for the future: try not to make too many new email addresses, try to reuse the old ones. And if you do have to make new email addresses, try to have a system in the passwords: eg. 'password' + 'key' + 'password', where the key is something unique for the email address like the last 2 letters or something. There are an infinite amount of other possible systems like this one and if you make one up yourself (that you can remember) it is even more secure.
Or just use a password manager like LastPass.
And besides that, it is always best to have 1 main email address, so you can use my second recovery option.
I hope this is the answer to your question and helps you.