All writers of fiction will at some point find themselves abandoning a piece of work - or find themselves putting it aside, as we gently say.
I do very few standards. Hardly any. Other people's tunes that I do are usually obscure tunes, for the most part, although I do a couple of Duke Ellington tunes that are well known.
The voice is an instrument that you really must take time to develop. It's like a good red wine Give it time.