Welcome to Just Answer and thanks for your question. You will need a check up with your doctor of course, but best guess would be a combination of your hypoglycemia, withdrawal symptoms from the Zoloft, and perhaps a little hypotension when changing positions. The first time it having too much to drink was also part of the mix. Usually hypoglycemics cannot handle much alcohol or carbohydrates at a time. Several small meals that combine protein with a high fiber carbohydrate are usually what is best tolerated.
No, the vision problem could have been from a migraine, or even from anxiety over the whole situation. Your doctor really needs to give you a thorough checkup to make sure there is nothing more wrong.