I eat lots of Plain Greek yogurt with good bacteria. I also did rectal probiotics for a few months, which saved me from recurrent C. Diff. after the antibiotics. I still take oral probiotics every day.
I currently do not have much symptoms of gastritis. No nausea or frequent intestinal irritation because the double dose PPI keeps the acid down. I don't need to take digestive enzymes anymore - stool tests show recovered pancreatic Elastase.
My headaches are just presentation of immune activation due to processes in the digestive tract. Contemporary medicine has no full understanding of how exactly that happens. In my case it is not related to hormones since it is abrogated by antibiotics, anti-inflammatories, and anti-acids.
Also, stopping the Temazepam seems to have improved my immunity - I am now more resistant to cold weather, my nose is not constantly running from the smallest cool wind, and not feeling constantly on the verge of "getting a cold" as I was on Temazepam. This seemingly immunosuppressive effect of benzos is not widely publicized. By the way I didn't have any "withdrawal symptoms" when I stopped temazepam cold turkey. I've taken it before that for several years.