It's looks like you're trying to find "worth" in external things but that will never work. A person's worth has nothing to do with what they're good at. I suppose it's pretty subjective but if anything people will judge you for who you are as a person and not what you're good or bad at. I think you're making unrealistic expectations for yourself. You can't expect to be perfect or good at everything. No one is.

There are times when you will mess up. You WILL mess up. A LOT. BUT that's normal. What's important is that you like what you do and you do your best at it. And if you do mess up you shouldn't take it hard. You did your best, you had fun and you'll do better. But if you do everything as some sort of way of proving yourself then you're not going to have good feelings either way. You won't be depressed because you failed. You'll be depressed because you didn't reach some unacceptable standard you set for yourself. In other words you're setting yourself up for emotional and physical failure before you even begin to act.

So don't be hard on yourself. Stop trying to prove something to yourself and just be in the moment. Act simply because you enjoy it. You don't need any other reason.