How to put a permanent end to all doubts and questions?
There is no other possible method.
Doubt and uncertainty is a necessary part of the life of any awareness that deals with reality.
The evidence for this is overwhelming, beyond any shadow of reasonable doubt, but not beyond absolute doubt.
At so many different levels uncertainty is part of existence.
Errors in measurement.
The slowness of our sensory apparatus.
We are surrounded by uncertainty.
To me, doubts and questions are a necessary part of the maturing process.
We start life as children without them, then they come on the scene. Some people seem to have a desperate longing to return to that childhood certainty, and will go to extreme lengths of self deception in the process.
If one is honest, doubts and questions are a necessary part of the maturing process.
Live with it.
Learn to love it.
It is what it is.