Hello and thanks for posting,

I am sorry to hear about your dad, and can appreciate your concern. These drugs do not mask malignancy, and common advice beforehand from endoscopy units, is to stop this medication 1 to 2 weeks before an endoscopy anyway. This is a close up visual examination that looks for areas of inflammation, (usually caused by gastritis). Biopsies are taken of any tissue, if necessary.

Do speak with your GP about your mental health, as it is good to get help, before anxiety or depression increases.

The NHS every mind matters website has some good resources.

Hope this helps, 

Best wishes,

Vanda