I'll preface this with saying I'm photosensitive epileptic, short-sighted, and also get migraines about once a year, so I do have a little insight, but it's the same conclusion as the others who have replied to you.
I've not had a problem in that dungeon, but I've long had preventative measures in place for being on computers. I have to adjust my monitor brightness to a really low level, which is also something you can try, plus I lower the in-game gamma levels to a comfortable place. I don't have any motion blurring, either.
Still, it wouldn't necessarily matter if I or anyone else had experienced what you did. You experienced it, and this is enough by itself. Many of these issues can be very specific. For example, my triggers for epilepsy will not be the next person along's trigger for epilepsy (just the same with my anxiety, as it happens). Your migraine trigger effectively belongs to you and only you; it may parallel on occasion to others, and that's about it. Which means it's always better to go and see a doctor about it. Only though proper diagnosis will a person be able to manage their condition as the diagnosis will be more accurate than uneducated guesswork. If you get a diagnosis, then you can come to the interwebs and ask people about their experiences with their condition, and come up with mutual coping strategies. You don't sound there yet, and with luck, you'll never have to be.
If this is the first time you've had a migraine, I can understand if you didn't want to call your doctor straightaway. You're fine now, hopefully, and perhaps you can chalk it up to a one-off. However, if you start to see funny shapes at any time (that's how I know I'm getting a migraine, funny little geometric shapes form and look like they're made of TV static snow), you feel odd, or it happens just like it did to you the other day, it doesn't matter if you're in a dungeon or anything else, get off all your screens immediately (yes, all of them, which means mobile/cell phones too), darken your room and take the rest of the day to sleep it off. Take paracetamol if you are able, and get a good glass or bottle of water to hand. When your head clears up, call your doctor (I'm not going to discuss medical costs, because I don't know where you live and am in no position to advise you on that anyway), and go and chat about it with them. Only medical professionals with your history and testing are going to be able to properly diagnose you should there be anything to diagnose.
Anyway, hope it never comes to that for you, and that you're fine now. :)
