As said, break the link to gold, if only as to ability to convert Marks and export, gold is a medium for the global trade era that died in 1914. Encourage trade in Marks with countries who are also gold poor, in effect create a Mark denominated trade regime. Stabilize inflation to a rate just above interest, it encourages some savings but more spending and erodes the value of both cash and debt.
Encourage exports and restrain imports. But understand that demand drives a modern economy and keep up spending to sustain wages that save and spend and pay tax. It is really just a shell game.
If you can keep your industry working you can as the USA and UK go idle steal markets. If your goods price less than domestic ones you might invade their home markets but tariffs likely have made that difficult. Accept barter and local currencies rigged to reciprocal purchases. Slowly create your own trade bloc that excludes the others.
The biggest source of raw materials and potential markets for many goods is the USSR, they are a pariah, but so are you, trade with them, they are able to sustain the industry through the depression if you can value everything right.