2 years after gastric sleeve, I am suddenly having dumping syndrome

Dumping syndrome isn’t very common after gastric sleeve surgery, especially not in the early stages, but it can still happen — and what you’re describing sounds very much like late-onset dumping. The symptoms you mentioned — sudden dizziness, sweating, fatigue, stomach pain, and liquid diarrhea — all line up with how dumping syndrome presents, particularly when it happens a little while after eating.
Even though gastric sleeve doesn’t bypass the intestines like gastric bypass does, the stomach is still significantly smaller and empties more quickly than it used to. Over time, especially as eating habits change and the body adapts, it’s possible for certain foods — particularly those high in sugar or simple carbohydrates — to trigger a rapid shift of fluid into the intestines. That can lead to the cascade of symptoms you’re experiencing.
It’s also worth noting that dumping can appear years after surgery, sometimes when the diet gets a little looser or after a change in medication, hormones, or stress levels. That said, this kind of dramatic reaction isn’t something to ignore. It could be dumping syndrome, but it’s also important to rule out other issues like low blood sugar (reactive hypoglycemia), bile reflux, or gastrointestinal infections.
If it keeps happening, track what you’re eating and when the symptoms occur — and definitely reach out to your bariatric team or a GI specialist. You might need some blood work, dietary adjustments, or possibly even medication to manage it.

Hello, I am sorry to hear you are having these issues. Dumping syndrome can generally be managed with dietary and lifestyle modifications. I recommend you follow up with your bariatric team not only for symptom management, but because they may have a different etiology than you think.

This may have direct relationship with what you are eating/drinking. If you did not experience this before you may want to look at what you are currently consuming and analyze this. 
Also take your time while eating and try to avoid very rich/dense food. I'm adding this video that also talks about the dumping syndrome. I hope you finde it useful. 
warm regards, Dr. Alvarez