student visa are under major scrutiny due to abuse of the system, you will likely have problems in the future when entering the country or if/when you apply for a more longterm visa, if you have any type of ED visa in the system that is not from a university.
they do give a damn they however cannot legally give out more than 3 months of prescriptions though as the system will not allow it, also last I checked doctors don't make laws and legislation, so why you are blaming them is beyond me 🤦
Not going to get through customs, even with tea money. If someone I know couldn't get a couple of inhalers through, or a different person I know couldn't get 1 month of blood thinners through customs it's extremely unlikely you are going to get 3 months worth of pill through.
Try Medisafe, it will probably still be "expensive" but around half the price of what you're being quoted in my experience.
I have taken many short trips around Thailand over the last few years and never had an issue regarding TM.30 when doing 90 days or the extension. (BKK)
That being said though, as with everything in Thailand, your mileage may vary