This explains how to disable 2FA if your phone is not available:
A couple of notes:
1. You will need to be able to access your email. If you're relying on LastPass to remember your email password, you'll be out of luck. So be sure you memorize your email password or have access to it.
2. The above link notes that the LastPass Authenticator cannot be disabled via email. Since you're using Google Authenticator, that doesn't apply to you.