Oh, I know that one very well. Or maybe I'm really just an imposter and have been lucky so far that nobody has called me out on it. No, seriously, I don't know how many nights I wondered why on earth they weren't calling a real doctor instead of me. Well, quite obviously because I was the one on duty, huh?
Today, after almost ten years of practising medicine, I'm mostly able to convince myself that I know what I'm doing. But sometimes, the voices of doubt return.
And like your narrator, I know the feeling of inadequacy concerning my writing. It doesn't exactly help that I don't write in my native language. But if I did, what would be my excuse for indulging in this particular pleasure?
You convey the feeling very well and I'm pretty sure, you're not an imposter. Just in case you were wondering