prospective English doctoral candidate: advice regarding weird relationship with potential advisor
I advise against sending an explanatory email. It will only make the waters murkier. An email can't correct what transpired. A better option is to meet with the professor in person to discuss your plans. This would give you a chance to demonstrate that you've changed and establish a new relationship with your professor. Don't spend time explaining your past failures. In your meeting, focus on what's positive in your record and your commitment to your new plans. Everyone screws up, you know. If this professor has the wisdom of his years and he sees a new spark in you, he will probably want to support you. Take a lesson from the past, forgive yourself for being human, and move on.