Should I Take My Previous Medication, Destop 60mg, Pepzym, Ganaton Or Continue With Nexum And Sert For My Persistent Stomach Issues?

Hi, I am having a really bad stomach problem, after eating most of the food I get upset stomach, specially gastic problem. My doctor told me that it is all due to anxiety and he gave me sert 50mg and Nexum 40 . I am taking Nexum 40 only but it is not completely healing my stomach and I am afraid to take sert 50mg because of the side effects may happen. Before this doctor, one doctor had given me destop 60mg, pepzym and ganaton 2 years ago and that medication had completely healed my stomach but what should I do now? Should I go for 2 years old medicine or go for new sert 50 and Nexum 40 ? But I am afraid of the side effects of Sert 50.