Even artificial sweetener leads to craving carbs in my case.
As for the "gut punch" though, sounds like gastritis or something. Unless you're being metaphorical. For me, water helps when I'm fasting and stomach pains start.
This feeling is so intense for me that I’ve come to believe it’s something to do with the carbs and my gut microbiome changing. There’s a 1-2 week delay between changing diets and having these hunger pains start/stop that makes this feel more credible to me than insulin response changes or diet boredom. But: one should not treat N=1 subjective experiences as having any real value.
My "hunger pain" is tied to the some combination of the gut biome and the blood sugar cycle. It initially insists that I should eat frequently. If I persist through it, then an hour or two later, it settles down.
Likewise, I've noticed an effect develop with artificial sweeteners where I can have small amounts without difficulty, but if I start consuming it several times in a 48 hour span, I get cramps.
In periods where I've become addicted to carbs hunger pain is much stronger, but I've been able to keep it down for many years now. So if you're getting it intensely, your gut is probably still reactivating to its old profile.
I believe restriction in the regular diet is one way of correcting it while staying in a routine. But I have also experimented with fasting, intense exercise, hot/cold contrast in the shower, and breathing exercises, and the common theme to each is to challenge homeostasis in some fashion. Obviously there's always some danger in going too far, but if our norm is total comfort, we can definitely drop some aspect of it from time to time.