the bad taste in your mouth is due to h pylori kit which usually contains antibiotics . pantoprazole
which is a ppi is a good drug in such situation along with h pylori kit. for change in stool color you must get yourself investigated a stool examination and liver
function test may help you , to know the cause for this . anxiety
plays an important role in your illness as it increases acid secretion , must bring your anxiety levels down by not worrying to much about the illness as the treatment seems to be alright and some relaxation exercises may help you in reducing the anxiety levels. anti- anxiety medications could be considered after consultation with a doctor.