The same thing you described to me once maybe 8 years ago when I used to work on my laptop at Starbucks and had a grande coffee too many. I thought I was going to go blind and was in bed the whole day. I searched the symptoms and the results suggested a migraine. I never had a migraine before, nor have I since. Since being on Keto 12ish years ago, I regularly supplement magnesium (helps with nail growth too).

My mother had migraines, so now I wonder if she was magnesium deficient, and if coffee/caffeine can sap your magnesium levels.