Applying for jobs is like going zip-lining, blindfolded, with your mother shouting that you're late to school, somebody playing country music from behind you, and a whole host of bees, buzzing impatiently for you at the end. In other words, it can seem as daunting as whatever frightens you the most.
I always have trouble, mainly because although I know what I can do, and how I can perform at a job, there are days when even I don't know if I can do x, y, or z. It might be obvious to friends or onlookers that I can do what I attempt to, but when you're still a little insecure from past times in your life, you're never 100% certain that you are who you market yourself as.
But the problem really begins in trying to market yourself in the first place. How can you say, with confidence, that your skills are, say, editing or writing, when you're not entirely sure of your skills (though people may tell you that you're good). Trying to market yourself as this person seems like a lie. You know it's not really a lie, but it's hard to tell even the truth when you keep doubting yourself.
The problem isn't that you're not as good as you really think, but it's the fear that you're not as good as you really are.
Conquering that fear might take time. But in the meantime, you're still marketing yourself, writing cover letters, applying to jobs. So how do you deal with a need (that is, the need of a job), and a setback (vast insecurity, self-doubt, and a constant feeling of bees when it comes to your self-confidence).
How do you market yourself?
Here's my advice: LIE TO YOURSELF.
You know your skills are x, y, and z, right? And they help fulfill someone's a, b, and c, yes? So, in other words, you CAN do what you claim you can. How you critique your work doesn't matter; you're going to be your worst critic, especially if you equate feelings of self-doubt with mother nature's best friend, bees. Sure, bees can seem frightening, especially if you're allergic, but odds are, you just don't like buzzing noises and have absolutely forgotten that bees pollinate flowers, which are nothing to be scared of at all.
Don't imagine bees when you feel insecure. Imagine flowers. Force yourself to see what you can do by how your actions have impacted your current workplace environment, how others see or appreciate your work, and what you REALLY bring to the table.
You're worth more than you might think. Those feelings of self-doubt aren't going to go away unless you work hard at combating them, but in the meantime, you can't let them impact the job postings you qualify for but are unsure of, connections you aren't making, or the resume with spaces you're not filling in, because you think your volunteer work, your skills, don't matter.
Trick your brain to think of flowers instead of bees. If you were reading your completed resume, who would you see? Imagine you are that person. Lie to yourself; tell yourself, I am that person, I have done x, y, and z, and it solved someone's a, b, and c. Have that confidence when you market yourself!
Because, the thing is, that's not a lie. It's the truth. Who you see on the paper IS you. If that person can accomplish everything on the job listing, then so can you. Go for it! If it helps, give that imagined person a different background story, a different way of looking at things—just be sure that it only stays in your head.
At the end of the day, you're still you, no matter how much your insecurity has muddled your perception. And that person is able to do things you might never have thought possible.