The HCl can get expensive. I started taking malic acid as a partial substitute for HCl. I buy it powered and put some in some capsules. It's quite acidic and I began taking 2 tsp in water but was worried about my teeth so reduced that to half tsp mixed with 1 x 5ml scoop of Xylitol in water.
I would say that you have an unidentified infection of your stomach just like many people on this forum which is causing the hypochlorhydria. All that you know is that it is not h. pylori.
I believe that the majority of people with hypochlorhydria have these none h. pylori infections of their stomach because hypochlorhydria is not a normal condition and it is not an inherent deficiency of certain people. It is just an unfortunate consumption of something infected with these bacteria which can have big consequences to people's long term health.
You will also have hyper permeability of your stomach which is what is causing all the problems with your hair loss, energy and mood making you feel like crap. Large food molecules are being absorbed into your blood stream which your immune system is reacting to and producing anti bodies. The anti bodies are affecting the areas where there are immune system regulation deficiencies specific to your body.
That is why all the normally recommended stomach healing substances have no effect! They cannot get through the biofilm protecting the bacteria. I believe that the bacteria benefits from the hyper permeability in some way and maintains it.
Please be aware that with deficient stomach acid levels your mineral and B12 absorption will be affected and you will most likely be deficient of any nutrient that requires stomach acid to help it's absorption!
What I recommend that you do until the bacteria can be indentified:
Take some easily absorbable magnesium such as mag malate would be beneficial and would help your thyroid and so would selenium. If you can get some magnesium carbonate and malic acid powder you could combine them and form a pure mag malate in a glass of water. Mag malate is one of the least expensive forms of highly absorbable magnesium, Source naturals tablets is what I use. I could not find an inexpensive form of magnesium carbonate, it cost more than mag malate tablets.
Some methylcobalamin (B12) also benefited me a lot and improved/normalized my body clock and also helps with TH1 suppressor T-Cell activity to down regulate the abnormal immune response to absorbed food molecules which is present when there is hyper-permeability of the stomach/gut. I take high doses of methyl B12. B12 deficiency can cause nervous system damage!
The zinc carnosine can help, I take it myself. It helps to reduce the inflammation which tends to help maintain the permeability. The more inflammation, the higher the permeability becomes. It works out expensive but helps a little. As you have gastritis it should be even more helpful so do not spare the capsules.
Finding out what the bacteria is, is going to be difficult. Without knowing the bacteria it makes defeating it much more difficult and almost impossible. I advise you to NOT start using the common anti bacteria agents because every time you fail and you will fail, the bacteria will adapt and become stronger and more resistant!!!!!
People will recommend things and you will try them and they will fail making the bacteria more resistant! Too many amateurs guessing and trying different things will cause you greater problems in future.
If you can get help then that would be most beneficial because these bacteria are very unforgiving and believe me, I have a lot of personal experience at this. They laugh in the face of common anti biotic sustances and shrug them off so easily! I have had some success but I held off destroying it which I regret. Please believe me, do not attempt to destroy this yourself because YOU WILL FAIL! Without knowing the bacteria or the strain you cannot find the necessary quorum sensing inhibitors which are an important factor in defeating it. Every fail will mean you are more likely to be stuck with it forever. Their aim is to survive and they are evolving closer to perfection with each iteration to do that. They will counter anything that you throw at them and your trial and error will render everything useless. Save it until you know what your fighting and know how to defeat it!