Hello, Welcome to HCM. Frequent urination is not unusual in winter season where our insensible loss reduces drastically. I do not think there is nothing like a overactive bladder in your case but it would be better to rule out diabetes by doing blood sugar and urine sugar for a safer side. For abdominal discomfort,you can take antacids like pantoprazole and rabeprazole for symptomatic relief and avoid oily-spicy foods rather take bland diet. However,there may be chances of diabetes since you grandfather had it but must be confirmed by above tests. This conditions usually self-limiting and symptoms may disappear by their own,so there is no need to worry much. You should see local physician for complete medical history and relevant test. Regards,