Need help understanding my symptoms (hyperPOTS?)

About two years ago, I had a purely gastrointestinal symptoms after eating just about any food. While I don’t know if that is connected to the episodes of today, I do know that the episodes of today are commonly triggered by my gut. That first set of episodes were cleared by a stack of sucralfate and anti-acids (not H2 antihistamines). after that, I went into remission for I would say at least eight months. I was able to eat whatever I wanted, including common college junk food binges and alcohol.

Recently, I completely lost my tolerance to alcohol and caffeine. Alcohol will immediately flush my face out and make me dizzy the moment it is consumed and very small amounts of caffeine (less than 50mg) will make me sweat and panic the same way 5 cups of coffee would have before. Diet products with sweeteners and carbonated drinks are also an immediate trigger for episodes.

The most worrying part by far is these unpredictable episodes that I have been getting for the last couple months. They will generally start off as fatigue and pressure in the head, almost like a migraine, but no pain. Eventually, they will work themselves up to nausea, numb limbs, pins and needles, inability to stand without passing out, and inability to consume any food without it worsening, especially foods with sugars like fruit snacks or gatorade. They also sometimes start in the gut, with tons of pressure and discomfort before boiling over.

These episodes last anywhere from an hour to multiple weeks. I have noticed, although I am not sure, that they generally follow a pattern of appearing after I eat a ton of hard to digest foods for weeks like fried foods. One of my worst ones did not follow any eating and just randomly came over me on the freeway while I was on my way to a weekend trip though, so I question the connection.

DURING THESE EPISODES MY BLOOD PRESSURE JUMPS MY 40-60 BPM WHEN I STAND BUT THERE IS NO DROP IN BLOOD PRESSURE.

In short, my doctor and every specialist I have seen have no idea what is wrong. Blood panels are perfect and endocrinology is stumped. Has anyone experienced similar? Am I correct to assume I may have some form of POTS?