Hi Dejibo and All!
I can empathize! I have these issues at times-- great difficulty with digestion, can't eat much, etc. (Neuropathies) My doc tells me it is gastroparesis. I have had the best luck with eating small meals and also with using magnesium citrate. Wow! What a difference for me! (I had been struggling with this for almost a year.)
I also sometimes use digestive enzymes. Probiotics, too.
Maybe you have tried magensium and I can tell you are very conscious of the amount of anything you might swallow. Good for you!
You have really been trying hard at finding what works for you!
I hope you feel better soon!
~DejaVu