So, first, I can relate to the problems with school. My headaches started during my senior year of high school and I technically missed more days of school than I was allowed to and still graduate (fortunately that didn't end up being a problem). However, if you talk with your teacher and administrators, I'm sure they'll help however they can. Fortunately, unlike college, changes can be made with regard to class requirements or even the curriculum that you need to complete in special circumstances (all students must be held to the same standard at the college level though, so that a degree granted to one student is equal to that same degree being given to another [also primary and secondary schools are legally required to make accommodations]).
I made it through high school and through two and a half years of college before it all became too much (though, if I had been more aware of my options, I probably could have continued). While those were difficult years, I still had happiness in my life.
Anyway, on to treatments. So, to break it down more concisely, you've tried:Preventative medications:
Amitriptyline (a tricyclic antidepressant)Abortive medications and interventional treatments
Gabapentin (essentially anti-seizure)
Magnesium (weak NMDA receptor antagonist)
Triptans (I never did well with them either)
A whole bunch of opioid painkillers
Now, many of the anti-seizure meds work my modulating Glutamate levels in the brain (mainly lowering them, or their effects). Magnesium does this as well by sitting on NDMA receptors. Glutamate is the excitatory part of the Glutamate/GABA neurotransmitter system. Some of them work in other ways, though. Aside from that, you have the traditional migraine medications like DHE and the triptans (as well as Topamax and Gabapentin, somewhat). Anyway, I'm straying from the point here.
Trying the anti-seizure meds is standard treatment and a good place to start. Since you didn't address this specifically, did the Gabapentin help at all while you were on it, even if it was only a small amount? I'd be curious to see how you respond to Topamax as well. It's one of the most frequently successful medications for chronic headaches and/or migraines, but also, unfortunately, one of the most difficult to tolerate. Even in patients who are helped by Topamax, a very large percentage decide to stop taking it due to the difficult side effects. You may have heard it referred to as Dopamax. This is because one of the most common (and most uncomfortable) side effects is cognitive impairment. One of the times I was taking it, I was working as a retail cashier and I found that I became unable to make change, even when the register displayed how much was owed. Weight loss (loss of appetite is more accurate) and depression are also common. I'm not trying to scare you by listing all of this; it's just important to know what side effects to be wary of and try to find a good dose that (hopefully) helps with your headaches while having bearable side effects.
I have to say that I'm surprised that Toradol is the only anti-inflammatory that you've been prescribed. It can be an effective abortive medication, but there are plenty of others like it that can be helpful as well.
Anyway, I won't breakdown your medication history further, other than to say that you should take solace that you've only touched the tip of the iceberg when it comes to treatment options, both medicinal and otherwise. Medicinally there are lots of other preventative medications to try, especially (but not at all limited to) other anti-seizure meds and other anti-depressants. Though it might not seem to make much sense, many people are able to manage their headaches just by taking an anti-depressant medication. There are also anti-inflammatories that you haven't tried and some can be taken daily. There are also medications like beta-blockers and calcium-channel blockers, as well as some more obscure cardiac medications like Mexiletine. Additionally, neuroleptic medication can also be helpful sometimes.
Non-medicinally, some of your options are things like acupuncture, biofeedback training, certain types of exercise, dietary changes, hypnosis, physical therapy, talk therapy, etc.
As I said, fortunately you still have a lot of options. However, I know it can be maddening as you try to be patient as you try them. So, one of the most important "treatments" that you can do in the meantime is to live as healthy of a life as you can. Your headaches are bad enough--they don't need anything extra to make them worse or to add to the suffering that you're already experiencing with them. So, exercise, stay social and active (that's something that can become very difficult over time), know your limits, try to get sleep that is regular and not too short or long, eat a healthy diet, and, perhaps most importantly, find whatever you can that makes you happy and brings you peace of mind and focus on it. Sometimes the worst pain can be quite bearable if you're in a good mood.
Be well and I wish you all the luck in the world,