Welcome to the site.
Well first of all I will encourage you to think positively and do not just jump to hasty conclusions about the outcome of your conditions which I will reiterate have the potential for full recovery provided you follow the already discussed drug regime and patiently wait for the outcome.
Now coming to your questions.
-- Well you see it is actually the other way round to what you have been told about poor outcome of drug induced GAD/Panic disorder/OCD/ Derealisation as compared to the outcome of such conditions which are naturally occurring. You see drug induced conditions like the ones you are having are more likely to have a favourable outcome as compared to naturally occurring conditions because here stressor is known which is a drug so by keeping away the stressor the outcome becomes much better.
-- You see although these conditions can occur in any individual but there are certain individuals who are more susceptible to their occurrence when exposed to particular drug acting as a stressor, so yes some people are more vulnerable towards drug induced conditions than the rest.
-- Well I will suggest that you continue to use valium on PRN basis that is as and when required basis at times of overwhelming anxiety because one should never let go of a drug which has been helpful for your cause in the past.
I hope this helps.
Wish you all the best.
No, unfortunately there is no such evidence which establishes that drug induced GAD/Derealisation as opposed to natural occurrence of these disorders more permanent. In fact as I had mentioned above too , clinically it is seen that drug induced GAD/derealisation comes with a better prognosis/ chances of better outcome in terms of full recovery as compared to the natural occurrence of the same.
Yes the Diurnal Variation as it is described clinically that is variation in your mood and feelings from high to lows is expected in your conditions. So this is not something abnormal but in line with your underlying conditions which shall go away once you start following the discussed strategy of management judiciously.
I hope this helps..