The way of learning

There is something that is terribly disturbing and frustrating to me. I have been studying for several years now and I am trying to think and delve deeper and I am forming an opinion, and not just through studying.
Then I talk to more competent people (or write a question on the website) and discover that my thinking didn't start and I was just wrong and deducing serious logical errors. And that's when I'm honest with myself and striving for the truth.
And even when my opinion is not wrong, there are still plenty of options and assumptions that are not binding, and it is possible to assume differently and conclude differently. And what does truth mean in relation to that?
And I wonder why I should trust myself. What place does that have when I strive for truth more than the opinion of others? After all, I am no more immune to error than anyone else.
And why should I determine for myself more than someone else would determine (in relation to the truth). And what place should be given to my understanding?