Hey there bobwobble! I'd like to give you a sincere welcome to our forums and I hope that in the future, you can be a contributing member of the community and we can all be of benefit to one another! Anyway, onto your problem...
It shouldn't come as a major surprise that Diazepam (Valium) is causing next-day drowsiness. Diazepam works quickly, but also has long-lasting metabolites working behind the scenes that have extremely long half-lives, namely, Desmethyldiazepam. As a matter of fact, Temazepam (Restoril) itself is one of the primary, active metabolites of Diazepam. You could say, in a way, that a lot of the effects that you experience from Diazepam are actually the work of metabolites like Temazepam.
The main point is, Temazepam is shorter-acting than Diazepam and does not possess these unpredictable, long-lasting metabolites. This is why Temazepam is typically used only for insomnia and not daytime anxiolysis. It should, in theory, work much better than the Diazepam.
