I feel I ought to throw one in here from out left-field... it's an answer, but not an answer to the question you actually asked.

The issue isn't 'not being able to see your expression', your issue is not being confident enough in the appearance of your own face.
Let me put this in perspective, using my dual/triple backgrounds as musician, actor & lastly, photographer.

40 years ago, the first time I ever heard my own voice on playback after recording my first ever studio vocal, I couldn't believe that was actually me singing. It sounded so completely alien.

35 years ago when I first saw myself on television, I had a similar reaction. I was making expressions I had never ever seen my face make... ever.

After all these years, I'm now perfectly comfortable with what my voice sounds like on tape... & I'm getting used to the expressions I make when I'm looking in a camera rather than a mirror.
But, to this day, I think I look like what I see in the mirror... yet everybody else who has ever seen me thinks those 'weird' expressions are a constant part of me.

I may eventually get used to it...

In the meantime, I've learned to live with it.

So... pucker up & click.
Forget trying to look like yourself in the mirror - no-one else has that view of you.

Free your face. Let it go. Play to the camera, not the monitor. Take 200 pics without looking at the results.

So long as you were shooting wide enough to allow yourself some movement, which you can crop down later, then you're going to have a wealth of material to pick through.
Some you'll like, some you won't.
That's life.

That's what every photographic model or actor has to do. They never get to choose what their face is doing right this second... but they've learned how to use what it does do to their advantage.