I can't believe in anything 100%. Even the most concrete physical “laws” are likely only be true within the filter of our own minds. What we vehemently believe is true is probably not so in objective “reality”.
There is probably no “solution” and the deeper you dive into physics and objective reality research, the more you realize how little we know. All the words in our human languages would probably explain nothing.
I can't say I don't believe in God but I will never accept an 800,000 word book written in an ancient language and then altered by man for millenia as absolute truth. Even if all the secrets of the universe were suddenly transferred to someones mind today, they would not have the language to express it.
The confusion that is modern physics cannot nullify the historical continuity and logical precision of Catholic theology. Objective truth does exist outside the minds of human observers and can be understood through sufficient prayer and study. The Devil exists and has used Kantian subjectivism to cloud the minds of modern men.