There are some blank areas in your question- like your age, duaration of disease and associated diseases like Hypertension
, Lipid and heart problem and present control of parameters like plasma glucose, B.P., Lipids, body weight.
Anyway what I presume you are not in good control. At first you have to control your parameters like plasma glucose, B.P., Lipids, body weight. If not controlled this may lead to many problems including the gastro-intestinal problems you have. Yes GERD ( Gastro esophageal reflux disease
is associated with uncontrolled diabetes
which is quite common in Diabetics may lead to Fissure in Ano
So I suggest -
Consult your Doctor for control of plasma glucose, B.P., Lipids, body weight.
Ensure daily bowel movement by increasing intake of fibre containing diet and exercise.
All The best.