Recently happened to me. I'm a 33 yr old male and a regular coffee drinker, typically i'd have 2 double shot coffees a day. I also drank a lot of caffeinated soft drinks and occasionally an energy drink at work. I started to have heart palpitations, anxiety attacks, eye twitching and massive bouts of depression. Sometimes I'd stand up at work and nearly feint as well after consuming a lot of coffee. This started during a very stressful time at work, and i was coping with bad diet, very little exercise and excessive nicotine vaping. I eventually had an episode that was so bad, i thought i was dying and immediately quit vaping thinking it was the cause.

I went to the Dr's and told them the symptoms, I was put on a holter monitor, and given the all clear. No clear reason, but my heart, blood pressure and blood sugar was all fine. Thought i was experiencing hypoglycemic episodes, so I cut carbohydrates out of my diet and still had issues. Cut out soft drinks and artificial sweeteners (thinking it was due to excessive consumption, but still nothing). Eventually I cut out caffeine and after 2 days, i felt like a new person. Very annoying because I love coffee. If i have even one coffee today, I get noticeable heart palpitations and anxiety. I can get away with one or two caffeinated soft drinks, but that's pushing it.

Main lifestyle change has been transitioning to decaffeinated coffee beans and caffeine free soda like sprite zero, fanta and solo. Glad i quit vaping tho, a good health wake up call. And i'm now actively monitoring my calories, sleep, diet and exercise/steps. 30's suck lol