Hi. I may or may not have the same condition you have, but with regards to self confidence, I always felt nobody could have had lower self esteem than me for the first thirty years of my life. I blamed myself for everything then: "I was too shy. I was too weak. I was unlikeable and unloveable. I was not perfect enough. I was too short. I was too anxious and fearful. I was too different. Everyone was better than I. I deserved to be punished." It was so bad that I thought even my abusive parents were not deserving of me, and I felt it was ok if everyone else criticized, rejected or bullied me, as I was acting like a doormat to be stepped on. My negative thoughts drained me so much that I had no efforts to give.
I did not trust anyone but my twin brother, and only talked a bit to him when it was just him and I alone outside in some more relaxing place. I never initiated any talk with others, looked extremely shy to everyone and avoided all, with me turning the other way or with head down and face red when others came near. If anyone talked to me, my voice would waver and I would utter a no, yes or don't know, depending on what they asked. Any non-question would be met with silence. I had no social skills, no trust that the other would like me or stay, and had horrible lifetime experiences with others, so it became habit to have negative thoughts fill and race through my head, hoping those persons would go away.
I will not repeat in detail how I changed my life around, as I posted that numerous times in this forum, but it did involve hitting rock bottom, then changing my attitude, prioritizing my efforts, having a goal or two in mind, creating a step by step plan to achieve that, but to allow for a change in the path and plan if things got in my way, with alternative solutions to get me back on track. In general, as each of us is different, and with different needs, abilities, limitations and desired approaches, what I tried and worked for me, may not be right or work for others. For me, I focused on numerous techniques and actions to worry less, be more positive and less negative, to increase my self-esteem and social skills, and to reduce other shyness traits, described elsewhere in detail in this forum.
The key too is to want or be able to change, with regards to self confidence, and with any other need or desires, as many here cannot change, or do not want to in the ways I mentioned. It seems like for every one that wants to and has changed in some way to function better, there is an equal number or more persons in this forum that is resistant to that idea, or who feels they cannot alter any ways, because of a condition, regardless of their own efforts or outside assistance. And then when one wants to feel more self-confident for instance, it is then from brainstorming to figure out what that means? To reduce shyness traits, improve language or social skills, feel more positive, to become more self-reliant, to reduce other mannerisms, to think clearer or quicker, to express emotions better, and/or to worry less, or a combination, etc.
I realize there are persons in this world who thrive under stress, who succumb to stress, or who are neutral to it and somewhere in between. In many cases there could be genetic roots, so who is to say certain predispositions can be changed without medications for instance, which I personally am not into for my own reasons, or without some other effective treatment. I just know when I was in my thirties, my entire perspective started to change after being at an all time low and after self-help attempts after deciding that is what I wanted and needed, and then my abilities became more. This created a healthier cycle, motivating me further, and resulting in a much better view of myself, others and the world. Whereas before I let the other persons, events, issues and situations control me, my state of mind, successes and happiness, eventually I started feeling I was in control of my destination, and not them.
Heck, even with family members that have so many issues, needs, and stressors, although there are days it can be hard facing these and having little time for myself, I do focus on the positives of each day, and of each person, including myself, any time doubt or stress tries to enter in. Our minds are a lot more powerful than we think. I feel we basically have four paths in life, to either: blame the world for everything wrong with us and our lives causing little desire then for us to change, blame ourselves too much and feel hopeless then to do anything about it, blame neither ourselves nor others but to just accept things as they are, or to see both we and societal members could be doing more, but with our efforts not mainly for the others to change, but for us to do things to become wiser and stronger.
I think for the two extreme personalities, in terms of self confidence-- the painfully shy and avoidant ones, and the arrogant and narcissistic ones-- although it seems like the latter is often the most successful, we can each define our own success and importance. Yes, extroverts with much self-esteem can have more opportunities in life, but they have many failures and anxieties in life, too, that we do not see. They may define their happiness and success by being seen as rich and powerful, and with highly professional status. In my case, I feel like a success regardless what anyone else thinks about me and my life. I survived a bad life, grew as a person and desired to assist and love others. I stayed true to my philosophy in changing for me and not others, yet I stayed still a great person in the process, but with me now believing fully I never deserved that bad prior life, as I was a good person then, too, unlike my skewed thought processes from before.