i have got very related problems. You seem to suffer from a sort of photosensibility/radiosensibility.
Your country, New Zealand, has signed and ratified the Convention on the Rights of People of Disability (2007, 2008). See:
Your state is obliged to do accommodations on your working place so that you are able to continue your teaching despite your photosensibility.
You have got the right to work fully integrated on your working place.
There must be organisations/places where you can go with your problem. At nearly all University Clinics (at least in Vienna) there are existing department for poisons at the working place and similar. Or the person responsible for the working personal on your school is competent for that. You should have the right for an exchange of the flourescent lights in the classrooms where you have to work.
If this would not be accepted, you would have to fight.
Maybe you can get a diagnosis soon.
Personally i am only in the diagnosis stage. There also seem to be different diseases conected with photosensibility, so that your special sensibility could be connected to another disease -not AT.
In my case i am almost sure, that i am carrier/patient of at least one mutation of AT Ataxia Telangiectasia. Radiosensitivity is one of the typical features of this disease, but there are many persons never learning that they are carriers of only one mutation of this mostly autosomal dominant heriditary ataxia, because one mutation needs not to be disease causing. I am sensitive on electricity, too, without special radiation. This causes walking problems and balance difficulties. Vertigo.
But - with one ATM mutation carrying (which is the case in so 1 % of mankind) you can experience some sorts of radio - and photosensibility without having the AT-Symptoms.
Now, what do you want to do first?
Please let me know, and then i would perhaps be able to write you more..