R.D.
What has worked to calm her down? How long has this been going on?
If you know she is going to wake up screaming between six and five why don't you set your alarm for six (or five to six)in the morning and wake her up? Then you're up, having already gone to the bathroom and brushed your teeth, and if you're waking her up with smiles this may help her not have such a rough wake up call. You'll also be in a better frame of mind.
All those negative incidents in your family are just as stressful to your sixteen month old as they are to you. The world is SCARY. Before waking up is when we dream, she's likely having night terrors and needs you to comfort her.
I know it's hard not to get upset with her but that only makes these experiences worse for her. She needs reassurance. "You're all right, Mommy's here, you're in your bed, in your room, at home with your family who loves you. You're all right."
My daughter used to wake up all the time screaming and crying, which of course was triggered by some serious change going on in our family. So, I do know what it is like to wake up to a child screaming and crying. Mine never remembers it, and I bet yours doesn't either (another hallmark of a night terror as opposed to a nightmare or bad dream).
Make yourself have the patience you need. If you feel like you don't then take a moment to calm down before going to her or before saying anything to her. Take deep breaths. It's better for her to scream and cry for one moment longer than to have you use an unkind tone with her. Go into super calm mode.
Think and feel more compassionately towards her. Help her have a happy day. Remember, she does not have the communication skills you and I do so she can not tell you what's been bothering her.
I feel for your daughter and for your family. I hope this helps. You and yours are in my prayers.