I used to be very shy as a kid. But I remember very clearly, one day in 5th grade, I realized that the easiest way to get people to be friendly to me was to be the first to say "Hi" to them. Our automatic response (at least in the US) is to say "Hi" in return and to smile. So whenever I'm in a space where I don't know the people around me, I start introducing myself first. It's actually much more pleasant than feeling awkward and alone in a corner even if it can get your stomach in knots the first few times. The "worst" that can happen is they won't respond and you'll be stuck back right where you already are. So why not take that super minimal risk?
It's amazing how this same principle applies to creativity as well. We can get so caught up in worrying that what we create won't be perfect that we hold ourselves back from creating anything at all. Our pens hesitate over blank paper.
It's very important to distinguish between worries grounded in reality (ex: making rent next month when you're facing financial hardship) and worries that stem purely from our imagination (ex: no one will ever hire you, you're totally doomed). Imagined concerns can have a basis in reality (ex: you're having a hard time finding a job because you're a fresh college grad and don't have the minimum requirement of 3 years experience for "entry level" jobs), but if we look around outside ourselves and see success despite similar circumstances, then we can know that there are paths forward. We might not be able to see them clearly, but the mountains blocking our view are larger in our minds than in reality. If you can distinguish between these two kinds of worries, you will be better equipped to pursue life. The worries might not go away, but they will have less power to hold you back. This mindset helps with everything from continuing to send out applications to putting ink to paper.
This is part of why I practice drawing without planning. As you should all know by now, I very rarely sketch out what I'm going to draw. The most I'll do is a very rough outline of the major themes. Every drawing is a practice in making a bold, confident decision. I can't take back a single mark I make since I do my drawings from start to finish in pen. After continuous practice I have complete confidence that whatever line I make, I will be able to turn the picture into something I like. I trust my hand and I trust my creative ability. As a result, I now throw out less than 1% of my drawings.
True confidence comes from trusting yourself and putting in your full effort. It takes practice and failure to learn like anything else. We have to learn that we can bounce up after failure. Of course no one's good at everything the instant they try it. We have to struggle and make mistakes in order to improve. We all have the ability to grow and learn. That's where self-trust comes in. It might be blind faith in some theoretical improvement at first, but eventually the results will come along and you'll have evidence to support your self-trust.
Whether drawing, writing, or in a room full of strangers, if you only listen to your self-doubt and mistake your mountain sized worries for reality, you will only be holding yourself back. Practice confidence in everything you do. There will never be a supporter of your goals and abilities as important as yourself.