Welcome to the Nexus, Purple Squirrel.

Sorry to hear about your migraines and challenging experience.  I started with DMT due to its similarity to triptan migraine medications.   I would be wary of a large dose myself if I felt it were a possible trigger, though I haven't heard of it being a trigger before, it might be coincidence. 

I'd recommend the advice you get here as these folks have a lot of experience with hyperspace and integration of experiences.  I've had difficult experiences before with other hallucinogens and really there is no need to be afraid.  You'll be fine.

If you need to stay away from tripping for a while or as long as you need then that might be a good thing to do.

Still, I suggest you might try tiny doses to abort a migraine.  I read from others' accounts that less is more in regards to using DMT to stop migraines, and have found that to be the case, from barely perceptible to light closed eye visual doses seem to work best.

Psilocybin from mushrooms seems to be better from most accounts for migraine relief and many find that they provide relief as well as prophylaxis from clusters and migraines.

Figure out what you're comfortable experimenting with, do your research.  If you want to never do psychedelics again, that's your choice and might be the right one for you. Once again though I'd like to say it again, don't worry, you'll be ok.