Do I have low blood sugar?

So, what did your doctor say when you reported to him/her that you'd been paying close attention to the symptoms that you were experiencing?

It IS possible that you may be suffering with hypoglycemia (lower than normal blood sugar levels), but the ONLY way to know for sure is by getting your doctor to run blood tests.

As to whether you need to get more sugar in your diet depends entirely on whether you are, in fact, hypoglycemic, and then which type of hypoglycemia.

There are two main types of hypoglycemia, fasting hypoglycemia, which is the much rarer type and is often caused by an insulin-producing tumor. This type MAY require surgery to put right. The second, and much more common type of hypoglycemia is called reactive hypoglycemia. This occurs when your pancreas overproduces insulin in response to the amount of foods and/or drinks that you imbibe. The absolute worst thing you can do with this type is to take in more sugar as you will be on a rollercoaster ride with highs and lows in your blood sugar levels. This type of hypoglycemia is controlled by eating smaller, but more frequent meals throughout the day. i.e. 5 or 6 smaller meals that contain fewer carbohydrates, but more fat and/or protein, which slows down the absorption of carbohydrates.

It takes a glucose measurement to verify hypoglycemia and the heart beating suggests to me that it's the more common Vasovagal Response often triggered by anxiety and stress. The water that you drank countered the momentary blood pressure drop.

You have anxiety issues.