Here where I work we have a saying, "What you hear you repeat, what you say comes toward you and what you write down comes to pass."
When you say deprecating or negative things about yourself you believe them more quickly. And when you write down negative things about yourself, they become self-fulfilling prophecies. So STOP it!
You have already proven yourself in our minds to be a quick study, inquisitive, capable, and you have a quick, intelligent sense of humor. Only the unteachable, know-it-alls fail when they try something new. Keep on going. You're going to be fine.
You'll likely end up more successful than many others, because you recognize you need a little help and aren't afraid to ask for it. Repeat after me, "I'm going to make it!"
