(Sorry for my own delay - had to take the child to football practise - American football.) :)
Although I can't give you a prescription (as would not any online Dr as you have seen - propranolol is non-controlled substance), I can at this point give you a solid professional opinion that would show merit to any prescriber that you should decide to go to.
-You have a history of anxiety that is not necessarily brief, and not "situational" in the standard sense and is brought on by ongoing life events.
-You have been prescribed propranolol (which is usually used for situational anxiety), and you have received no relief.
-You have had a trial with Valium (diazepam, 5mg tid anxiety) and Xanax (alprazolam, 1mg qhs prn sleep/anxiety) and both have provided significant relief.
-You take no other chronic medications, have no other significant medical issues, show no history of abuse, and react well to benzodiazepines with a proven history as described above.
-You used diazepam 5mg three times daily for 'weeks' and describe no symptoms of withdrawal upon discontinuation
Valium is fast acting (30-60min), has a long half-life meaning it stays in your system for a long time (much longer than Xanax) - days as opposed to hours. If you happen to miss a dose, withdrawal symptoms are greatly reduced with Valium.
Similarly, due to its longevity in the body, when you discontinue, there is little likelihood that you will withdraw (given your history). Studies show that benzodiazepines can be taken by patients (not all patients, ofcourse) for a few months without experiencing significant effects upon discontinuation.
For anxiety, the minimal dose of Valium would be 2mg bid (or 2mg twice a day). You may well do just fine on this dosing regimen with a reduced risk of compromising side effects. You have taken 5mg tid (or three times a day) and done well on it.
My recommendation, then, to your prescribing provider is "diazepam 2-5mg bid-tid prn".
It will be up to your prescriber to write the final order of this med. My account above should greatly facilitate your access to this needed medication. -DrMike