Hi Doctor,my Name Is Subho Biswas.my Age Is 23.weight-64kg,hight-183cm.since Last

Hi doctor,my name is Subho Biswas.my age is 23.weight-64kg,hight-183cm.since last month I am suffering from FBD(Functional bowel disorder) & as per doctor prescription I am taking Rabeprazole-20 before breakfast,and Normaxin before lunch and before dinner.
But still I am not recovering complete ly.sometime stomach pain,sometime had feeling of poty,and sometime uneasyness like i am going to faint,and frequent palpitations.
And this things makes me so uncomfortable leading into a daily reguler life.