I am not a doctor but you might want to look into Adrafinil.
It is a precursor to Modafinil and gets converted to modafinil in your body.
https://en.wikipedia.org/wiki/Adrafinil
Apparently your liver converts it, which means work for your liver and less bio-availibilty ?
But even modafinil is not a cure-all. There can be dependency problems.
It is powerful at first and it does make a difference, but I just don't know if it would help with a chronic condition in the long run.
Have you tried going after the root cause?
There are some experimental PTSD therapies that have good success rates depending on the cause or origin.
i hope you find relief soon.
-al