I don’t see it as complaining. And your feelings sound very natural to me. I hope you continue to cope.
I suggest allowing your employer or supervisor to decide that. If you’re able to acknowledge your worry and give it compassion, remain focused on learning, then you’ll continue to improve at your job. Most jobs that challenge a person are overwhelming. You’ll notice that gradually you absorb new information, and your brain gets used to it and thinking in a different way. Then one day soon, you’ll realize that the feelings of being overwhelmed are gone.
Please remember to give yourself credit for having the courage and desire to make a better life for yourself and facing the obstacles that go along with it. It’s ok to be afraid, that’s part of being human, and confronting fear is what courage is all about.
I’m glad you posted an update.