I'm writing a short story and my first draft was reject for grammatical errors. I don't know when to use a comma or a different punctuation mark when two characters are speaking. This is from my story:
"Answer me," he commanded.
I cleared my throat and whispered to him "I understand."
"Is this how you are to address me?" He asked, his voice persistent.
"I understand, Sir." I tried to open my eyes. My vision was clouded with tears and as I moved to wipe my eyes, he released his grip but did not move his body from my personal space. I quickly wiped my tears and finally looked at him.
After "Answer me", should there be a comma or a period, and why? How do I know which to use? Thank you!
BTW the story is light BDSM erotica.