The medication you're waiting for will not come in the future, either I mentionned it in my comment either it doesn't exist. Chances are moclobemide or (I'd try first) selegiline would be a better feat for u. As I said the drugs I mention can be used not necessarily to replace but to lower your stimulant dosage and therefore anxiety.
As for the anxiety it can itself be mitigated, by taking low dose clonidine (slighly sedating) or guanfacine (less sedating), and they can be bought OTC.
Many people report magnesium-l-threonate reduce stimulant anxietu (which is logic since it is a weak NMDA antagonist). If you want more strong solution against stim anxiety, either use a potent NMDA antagonist like low dose memantine (cause brain fog the first weeks) or use a low dose beta-blocker (some again being OTC)
Also vyvanse cause less anxiety than adderall.
As I said, zinc supplementation can reduce your adderal dose by 1/third and hence side effects.
There are also mild efficacy blunters, such as l-theanine, pine bark extract (promising) or ginkgo biloba.
If the stress is due to vasocontrition you might wanna try cialis.
then there are atypical non-addictive anxiolytics (afobazole, opipramol, etifoxine (beware liver monitoring), emoxypine, tofisopam)