Meds required approval but I’ve run out of time (Singapore)

Yes, I should’ve known about the application process but, regrettably, I misread and didn’t realise some of my meds required approval. I’ll suffer the consequences need be but I want to make sure I’ve tried all that I can.

I’m from Australia.

Meds I’m on (6 weeks worth):

\-Sertraline 300mg
\-Brexpiprazole
\-Modafinil
\-Methylphenidate Hydrochloride, (Concerta 54mg, Ritalin 10mg)

I have a letter from my GP cementing they were prescribed to me but we’ll be there in 4 days, not long enough to complete the application.

We are only staying overnight in Singapore to catch another flight the next day to London but there are no transit hotels available. We were thinking we could stay 24 hours in the airport lounge but I don’t know how we’d receive our bags or if it’s allowed in the first place. I could get the medication needed mailed to the next location from here, possibly, but it’d be a last resort.

I can last a week of some of my meds but with the full holiday being 6 weeks I’ll suffer crazy withdrawals and not be able to function.

We’re trouble shooting other avenues but I figured I’d ask.
Any ideas on how to go about this (legally)?