Have you tried the Anticholinergic Trihexyphenidyl? (Artane)

I have tried it at dosages from 2mg to 6.25mg. It is a pretty potent antimuscarinic antagonist with strong activity at the muscarinic acetylcholine M1 and M4 receptors

At 1mg-4mg it is pretty good at reducing general and social anxiety and even better for insomnia, but anything higher than 6mg is risky deliriant territory, like high doses of DPH etc and Atropine. Doses at 7-8mg are not bad, but that is when it starts to gets sketchy and not really useful anymore. Doses like 10-30mg in one go is just a full blown deliriant trip, lasting up to 2 days, not recommended.

6.25mg is the max i tried, makes my muscles feel like jello, loss of balance, vertigo without nausea, and a slightly deliriant, on edge type of headspace, although manageable, without hallucinations and somewhat pleasant+still effective.

It is easy to get prescribed off label, because it is not addictive or very recreational, and rarely misused. It can cause tolerance though.

Normally it is prescribed to treat parkinsons, at doses of 1-10mg (higher doses pread out over 24hrs). For me taken for anxiety and insomnia, a dose of 1-2mg is more than enough without too many side effects or recreational effects.