What sleeping med is fine with gastritis? (mirtazapine?)

My doctor has zero clue about either unfortunately.

I am getting better. Like, a lot better. But I had an acute sleep disorder in September and October (the both phsical physical and mental stress of which I assume to be the cause for my gastritis). Sadly now I suddenly failed to sleep again, and took one Oxazepam (a weak benzo). Got 4 to 5 hours of sleep at least. Now my stomach is also a bit more nauseous of course from the worry.

Benzos are my emergency pills though, neither a long-term nor a short-term solution. I had been using doxylamine as emergency pills before but they are antihistamine so I don't wanna built a tolerance with such a strongish antihistamine if I maybe need weaker ones like Famotidine in the near future for my tummy.

Problem with Mirtazapine is its side effect of overwhelming hunger. Because right now I am well below my needed calories since I had to slowly begin my elimination diet from anew after I got worse again even though I was basically over it. Something I ate didn't agree with me, I assume it was the eggs (my symptoms switched from heartburn to nausea weirdly). Now I am already worrisomly underweight so gaining it would be a win, gaining weight is a "mission" of mine, and I hear mirtazapine also helps with nausea. But some speak of such a strong hunger they can barely stop eating, and crave fatty and heavy food, and a few speak of hunger pains keeping them awake at night. I mean... that's shit with gastritis, I can barely eat as it is.

Also, mirtazapine is a longer-term deal because it takes a while to kick in and is not awesome to get off of. So I wonder if there may be something better for mid-term. I think I'll try melatonin tonight. My fucking psyche man lol. 28 days of good sleep since I stopped taking sleeping meds, and now the thoughts make me crazy again. :T