Re: metformin side effects, anxiety, surreal?
Are you testing your blood sugar levels? And if so...how often? It's possible that your blood sugar actually went too low, which could have caused the odd, detached sensation and the surreal feeling. Also, when the blood sugar goes too low, the body produces more epinephrine, which makes you feel very anxious. At the same time, if the sugar goes way too low, the liver will release stored glucose, causing you to rebound and become way too high, which could explain why you felt so exhausted the next day.
Without proper monitoring of blood sugar when one is on medications, whether oral or insulin, one is basically groping around in the dark. If you're not already testing your blood sugar at least 2-3 times a day, I would suggest you do so, especially while working up to a therapeutic dose of the metformin. If you find you go low at a certain time of the day, you can eat a little bit of food to prevent that from happening.