I experienced this with 2C-E, it was my most chaotic and psychedelic +4 experience of my life. I had previously determined that "god" (the universal consciousness" is all that exists, and that we are all that experiencing itself subjectively, simultaneously, and that excperience was beautiful, life-affirming and filled with light, but then with 2C-E I went past the oneness into the void... I experienced the dissolution of the universe entirely and then there was only a yawning black void of nothingness where I was a singular point of awareness endlessly falling in the most crushing void of loneliness... I deeply lamented that I had shattered my beautiful illusion which I had created in order to escape this loneliness. Of course it came back... and I was never so grateful to exist in the "ordinary" sense again. I would have been glad to return as someone in the worst imaginable situation because it would have been better than that horrible void of nothingness. I concluded from this that the reason for the material universe (matter/energy and its condensation into the hologram we see today) is simply to escape absolute nothingness. I/We brought it into being in order for there to be something instead of nothing.
I also considered killing myself on the way to this void, hoping it would stop the 2C-E's process before it was too late, because when I neared it I remembered, before it fell away completely.
The "trick" is that we ARE all "god" (but I prefer the term universal consciousness because of the fact that the term "god" is loaded for us), but we're also not god, because we have constrained ourselves dimensionally to create the illusion of separation and individuality.
Personally I have never experienced any amount of vasoconstriction from MXE... I do get it rather easily in general too.