I was placed on oxazepam (Serax) 1 week right after my first seizure, and was later put on Depakote. I received CAT scans and eventually an MRI after being rushed to the ER after convulsing with a heart rate or 140-160 bpm. I asked the doctor about obtaining a long acting benzodiazepine (diazepam...ect) while in the ER after I told him about my use of thienodiazepines. The CAT scans are rapid, taking 15-30 minutes depending on how recent the tech is, MRIs usually get taken weeks after so you are probably about to undergo that procedure.
As far as short acting trips, I would go for something that lasts no more than 4-6 hours ideally. I was a huge fan of 2C-C before I was diagnosed, and it has a duration of 2-3 hours intranasally/plugged and 4-6 hours orally. Other phenethylamines could be usable such as 2C-B and 2C-D. DMT might also be a good choice at doses below 40-50mg of freebase (sub breakthrough doses). Psychedelic mushrooms may also be possible at a low dose (titrate up) in addition to: 4-AcO-DMT, other tryptamines that have a shorter duration. I would stay away from NBOMEs, DOX series, LSD and analogues like LSZ/AL-LAD, 2C-E/P, and Mescaline.
As far as stimulants go, stay away from cocaine, or other drugs which also alter sodium channel receptor gating (Lamotrigine regulates NA voltage). Short acting stimulants are best. You should be able to use instant release amphetamine (Adderall IR, but I recommend dextro-amphetamine) and Ritalin (though I recommend Focalin aka the dextro enantiomers). Can't think of examples offhand but promotion of the SVA2 vesicle release could also precipitate seizures (levetiracetam inhibits release to function). Psychoactive substances which exert affinity as GABA A antagonists or induce re-uptake of GABA by neurons. You may find higher stimulant dosages are required as anti-epileptic drugs (AEDs) work by modulating/regulating neuronal activity.
I have experimented with MDA and MDMA a couple of times since diagnosis, never had a significant problem. AEDs change the nature of them and decrease the experience overall, they were not as enjoyable. Benzodiazepines are not recommended but you can take them once, maybe twice every week or possibly 10 days. Save them for when they are medically necessary (if/when you have another seizure), you will likely be given diazepam (Valium) or lorazepam (Ativan) if hospitalized. Stick with long acting benzos in this case, blood plasma concentrations which drop off abruptly are not recommended. Do not build a tolerance or become dependent again, that is among the worst things to do.
Opiates/Opioids slightly lower the seizure threshold but I have had no problem (Depakote and other GABA A re-uptake inhibiting drugs) may slightly potentiate the sedation though. Opioids such as Tramadol and the like which have particular affinity for induction of serotonin and norepinephrine release are questionable, be careful. I have not used NMDA antagonists (Methoxetamine/Ketamine) since diagnosis, and am not sure what modification of NMDA/AMPA/glutamate could potentially do to the seizure threshold. Seizures are essentially abnormal electrical activity in the brain which usually manifests as patterns/rhythms. They may become generalized and result in a tonic-clonic seizure as the activity potentially resonates and spreads across the cortex, temporal/parietal/occipital/frontal lobes and the cerebellum. That summarizes my knowledge of substance usage in epileptic subjects.
I have felt odd/dysphoria on some substances (high doses of cannabis but it was likely paranoia/anxiety, high doses of more selective kappa opioid agonists, prolonged stimulant use for more than one day and comedowns). When I have a seizure, I usually start by losing my short term memory (likely of temporal region origin) followed by change of my sense of touch/feeling (parietal) and then my vision (occipital region). Lights get brighter in my vision, shadows may become prominent or appear, everyday objects look novel. I then taste blood and feel it running down and pooling in my mouth (taste of metal). I lose my ability to speak/understand language after a tonic-clonic and lose my ability to recall/plan events.
It is a good idea to have short acting/rapid onset benzodiazepines on hand (etizolam but not sure of its anti-convulsive potential, alprazolam aka Xanax, lorazepam, etc). That is why you must not become dependent on them or misuse them at all. You will need them to work normally if something happens. Sublingual and IV benzos will abort a seizure and prevent more for occurring while they are active. Look into them especially long acting ones like Klonopin, but medical professionals may be hesitant to prescribe if you told them about your usage unfortunately.
Will epilepsy change your lifestyle? Yes. Will the AEDs suck as far as side effects? Yes. Stay positive, take action to prevent more seizures from occurring. You will get it under control, do not become depressed and hopeless like I did. Consider looking into starting a ketogenic diet. This post is comprehensive to say the least haha....I truly wish I had this advice available to me after my diagnosis!
Why I am qualified to say any of this? I am one semester away from earning my Neuroscience and Biology degrees. I am well versed in the scientific literature, I have spent many many hours crawling through research to learn. I have been diagnosed with epilepsy for almost 8 months and I am knowledge able on the subject. I conduct studies using EEG participants, including myself, and research electrical waveform reading discrepancies in epileptics versus neurotypical individuals. I also study autism and have been published in literature. I am well versed in organic chemistry, molecular biology, cognitive neuroscience, and (psycho)pharmacology.
I really hope that this helps you and anyone struggling with epilepsy. This is off the top of my head and impromptu, I have sources for all of this if you need them. This is most of the generalized knowledge I have on epilepsy. You may not find some of my experiences to be the same as yours, experiment wisely and with caution. Take time to get re-acclimated with your body.