This is a very interesting read as well as terrifying in such situation. The pace is good, the mood is tense and the chill of his overbearing is oppressive. So great job there!

As for the structure of the writing, I feel like it's a bit jagged and could've been more concrete. While understand the pace is panicky and abrupt, I'd suggest a more fluent take on the characters. It's clear there are some very obvious cues, but not everyone may take the hint of the more subtle meanings you're trying to convey. So I'll take some examples of what I mean and rewrite them.
--
So you wrote:

"I'm in a terrible situation," I whispered, petrified that Ken would hear.

"Do you need to call 911?"

"No, I'm too scared."

"Tell me everything."

--

Here's how you could accentuate your scene.

--

I whispered in the softest voice I could breath between my dried lips. The terror I felt was petrifying, Ken could take advantage of this situation without warning if he found out. So I spoke barely a whisper and said, "I'm in a terrible situation." I looked back as if fearing his shadow would expectedly crawl into my personal space. The voice that spoke back seemed to be holding a tone of worry that was difficult to mask as simple concern.

"It's going to be okay, just breathe. Do you need 911? Please tell me the truth."

"I-I can't, not like this. I can't do this!" I felt heat blooming in my cheeks, the salt from the tears pouring down my face stung as the blood rushed to my face. My lungs became ice as I heard Ken shuffle around, there was nothing left to feel. Nothing else to hide.

"Tell me everything."
--

Hope this helps! :3