Yup sure do!
There have been times where no matter if it's vaping freebase or smoalking changa, at some point an uncontrollable purge is necessary. I seem to be moving out of that now as the last few times I've done just DMT I have not needed to purge, and the last several times with changa, I've either not purged or only done so a little.
I will second the notion put forth by SIB that certain psychological states and conditions will lead to increased nausea. I have generally high anxiety from high sensitivity, have a sensitive gut, and hold a fair amount of stress in my stomach. So it's been a work in progress learning how to manage it in all situations, in regular life and psychedelic states.
When sitting/guiding others, it also happens occasionally. I tend to keep a bucket with a few drops of essential oils in it around whenever DMT is going to be used, whether by me or someone else.
Ocular waterfalls are common for me, and yawning too.
If I may, try focusing and breathing into and through the sensations involved in vomiting, just allowing them to be, withholding usual judgements that come about when this occurs, but still seeing how long you can stave them off. It's easier said than done and takes practice, but with diligence, it does work.
One love
What if the "truth" is: the "truth" is indescernible/unknowable/nonexistent? Then the closest we get is through being true to and with ourselves.
Know thyself, nothing in excess, certainty brings insanity- Delphic Maxims
DMT always has something new to show you

Question everything... including questioning everything... There's so much I could be wrong about and have no idea...
All posts and supposed experiences are from an imaginary interdimensional being. This being has the proclivity and compulsion for delving in depths it shouldn't. Posts should be taken with a grain of salt. 👽