Interesting situation (and well stated).
So you want to convince yourself that you know nothing?
…except that life and family is good (I guess).
“I want to believe that all mathematics is indeterminate except 2+2=4 and 3*3=5.”
…hmmm…
I suspect your “starting all over” option would be the better one.
A person cannot change anything of himself without discipline, “faith in oneself”.
But then a person who wants to change himself has faith in what exactly?
Suggestion;
Get a blank bound writing booklet and promise yourself that you will write nothing in that book until you are 100% absolutely certain that it is either true or valuable, depending on which concern you are seeking, truth or value.
Of course, depending, you could possibly just forget the book because it would take quite a while before even the first entry, so it helps to have incentive. Two historical incentives have been;
“don’t speak until you speak absolute truth” and
“don’t move until you know absolute value”.
Of course you will want to compromise, maybe with;
“speak only of niceties until you know an absolute truth to speak instead” and
“don’t eat until you know absolute value”.
But I suspect you would want to compromise even further.
But you get the idea, right?