Why should you finally stop exposing yourself to self-criticism? It's quite normal. You cannot believe that you will succeed, otherwise it is fraught with excessive self-confidence. And it, in turn, will lead to frequent failures. By questioning your every action, you automatically become an expert of yourself. On the other hand, it is important that these doubts do not go beyond the reasonable ..
And here I come to the answer to your question. At one time, I also suffered from this problem. And to be honest, the echoes of it still appear. But one day I came to the conclusion that I myself could not objectively analyze myself. For example, an action or other product of my activity that I considered completely unsuccessful, others might see as ingenious. I decided that I needed an advisor who would objectively consider each of my products that I question. Moreover, the advisor should not be interested in convincing me of my genius. That is why I often asked for advice or comments from people with whom I am not very close, but I am confident in their objectivity ..
But this is my story of gaining confidence. I don't know how it will help you, but why not give it a try?
It is true that nothing happens when we do not feel the strength in ourselves. If you consider a person separately from other people, then if you want to feel the strength in yourself, you just need to go back, you should start to succeed (in any of your activities), then your self-confidence will increase. Here you need to go gradually towards the goal, in order to start to get something, you need what is called "slipping" in this. That is, if nothing works, do not look at anything, just try to improve your skills that will help you achieve the task, even if you do not believe that something will work out, then start not from confidence, but from naked rationalism: "So what I need to do to get this-this-this, just schedule and follow through. When something starts to work out, you yourself will understand that you did everything right and got off the ground. See doubt and uncertainty not as weakness, but as strength. If you are not sure that the event you want will happen, then make every effort to make it happen. That is, your doubts should motivate you to do everything as efficiently as possible, and not push you back. Just be careful: this way you can become a perfectionist) I'm not kidding. And that's not good either. If something did not work out, do not give up, but learn from this - from every mistake you make, the more lessons you learn, the faster you will develop in the future. In general, at first, you just need to forget about feelings and do, do, until you succeed, overpower yourself. Be an active person, the more the number of areas in which you try yourself, the more likely it is to find the one in which you will succeed the most and best. It is worth stopping at it, then you will forget about self-doubt. If we consider you as a part of society. Then surround yourself with people who will dispel all your self-doubt, those who, when you look at them, you will want to start doing something and not stop. Let your friends be your support ... As far as I can remember, I have never been self-confident, but all my doubts forced me to find ways to solve the questions that arose before me so that I could not think about self-confidence. Of course, this requires much more strength, and I do not recommend living like that. Over time, you will understand that being insecure is simply irrational and stupid, in other words, allow yourself to be moderately "cocky" and self-confident in your thoughts and actions, because it is far from always possible to go on naked rationalism. Do not be afraid, over time everything will fall into place, the main thing is not to forget what you want from life - never, and sooner or later everything will work out. Good luck!