Shaky & racing heart after drinking even small amounts

I’ve been trying to figure out why my body reacts the way it does when I drink. I hardly drink and when I do, I have maybe 2-3 drinks – beer or wine. I drink tons of water (I normally drink 2 liters a day) and eat. But without fail, I always feel horrible with the following symptoms:

-Headache, racing heart (90-110 for several hours), shaky, and insomnia

I’ve gone to doctors, including a cardiologist, and have gotten zero answers. I don’t get rashes/flushed, so I don’t know if it’s an allergy or intolerance. None of my family members experience the same thing. I’ve tried taking antihistamines and Party Smart but they don’t do much – Party Smart stops the headache, but not the most distressing symptom, which is a rapid heart rate for hours.

Today, I had two beers at a birthday (about 5 hours ago) and I have a headache, my heart rate is 100bpm (my resting is about 55) and I feel shaky (imagine drinking way too much caffeine.

What is the deal?