HUGE HUGS
I am always turning up with my rollator at any hospital scan and head treatment because I feel rather woozy, off balance and disorientated afterwards and sometimes really struggle to find the exit.
The MRI is worst in that respect although I can usually cope and let the noise either let me soar or come out through my feet, depending on the rhythm. Or I took a dive in warm water (in my mind) with the one MRI I had in a different hospital, which had a somewhat sour sound that rather needed me to try to dampen the effect of the sound in my mind a little.
Your reaction is not at all uncommon when you struggle to cope with the noise from a MRI, which differs from machine to machine and can be extremely loud and unpleasant; especially with older models. Thankfully, any other scan is a lot less unpleasant, just as a heads up.
Right now, please make sure that you keep the light and any noise down as much as you can and try to rest and relax your neck and shoulder muscles from any stress tension. Migraines are are very painful, so much so that they can make you sick. That is pretty common and deeply unpleasant. Migraines come and go in a rebound cluster.
If you are having an MRI during a migraine cluster, then it would be rather likely that you have a bit of an over-reaction.
What you describe is very much in line with the few stress related migraines I have had in my life but it is NOT at all similar to my own experience with my own brain tumour and badly swollen brain, if that helps you?
I can of course not comment sight unseen and my own experience may not apply to your situation at all; but having had first hand experience of either I hope this can help you a bit? My own migraines have always been a reaction to a major stress situation when there was no suitable bug around I could come down with badly.
It is however important for the medical profession to make sure that nothing crucial is missed and that anything worse can be ruled out straight away. Try to see the MRI as a safety insurance rather than as a threat.
I do however wish that some people had a bit more sensitivity and commonsense...
What you could do if you feel that it would help you is to write a letter to the relevant MRI department. Mention your situation and how it has made things worse for you and ask them politely to please bring it up at their next staff meeting. Especially as anxiety is generally on the rise, that it is making the experience worse for any sufferers and undermines the good work they are doing. (Always add something complimentary so your point is accepted better.

)
I did that with my sensory overload overreaction at the start of my radiotherapy, and it was taken seriously.
PS: I had my own head MRI with contrast last Thursday right in the evening before a major storm front, which didn't help things at all and ended me with a rather bad night and some extra brain swelling pressure on top of my storm headache.
Still waiting for results but taking the fact that I haven't heard back from the team before my scheduled review as a positive that there is nothing seriously wrong and I can hopefully avoid going back on steroids although the brain swelling is still there for now the second week; but at least it is not getting worse.
PS2: One way I face my own worst case scenarios (from the possible cancer death of my hub to my own or the potential loss of a special piggy) is to face my fear head-on and and to ask myself whether I am able to bear this fear. If I can do that for a few minutes, then I know that I will have the inner strength to cope with whatever the worst case scenario throws at me - and anything else is a lot less bad...