Nausea waking me during the night due to anxiety

If this is any help, my appetite decreases dramatically when I'm anxious. An empty stomach can feel like nausea, so I've learned to eat a little something when I wake up in the night feeling sick. Have a think about what you're eating and when. It might help a little.
House moves are a bind and I don't envy you. But eventually it'll be over and you'll be able to sit in your new place and recover from the sheer drudgery of it all!

Anxiety and stress will nearly always intensify, when you are anxious and or stressed. In the last 18 months we have been dealing with the house purchase/sale stress, house renovation stress, plus DH's poor health.

I am prone to hyperventilating when stressed. the main symptom is heavy breathing as if you are out of breath. Last year, according to DD I was walking around all the time chuffing like a train. Over breathing causes dizziness and I was reeling, and very usteady on my feet

This year most of our problems are resolved, and I am breathing normally most of the time, just the occasional bout.

I am sure you will find a similar pattern with your nausea, although CarrotTop's suggestion of eating something small, possibly a ginger biscuit is seems very sensible.

Moving house is very stressful. You're probably anxious without realising it. It's a good idea to eat a biscuit.

How are you on 22mg of Mirtazapine? The tablets are 15mg, 30mg and 45mg.

Magnesium bisglycinate. an hour before bedtime ,Should help

CarrotTop

If this is any help, my appetite decreases dramatically when I'm anxious. An empty stomach can feel like nausea, so I've learned to eat a little something when I wake up in the night feeling sick. Have a think about what you're eating and when. It might help a little.
House moves are a bind and I don't envy you. But eventually it'll be over and you'll be able to sit in your new place and recover from the sheer drudgery of it all!

Good advice.
A light snack before bedtime is a good idea too, cereal or toast.
The stomach is never empty, it contains acid sloshing around and awaiting its next meal to digest, so that can make you nauseous during the night.