Option 1

Approach your colleague immediately in person, sincerely apologize for the accidental email, and explain that it was a private draft not intended for their eyes, offering to discuss your concerns constructively.

Option 2

Immediately contact your manager or HR to report the accidental email and seek their intervention, explaining the situation and asking them to mediate the conflict.

Option 3

Avoid your colleague, hope they don't bring it up, or wait for them to initiate a conversation, pretending the email was never sent and focusing on your work.