Unproductive
Part of speech: adjective
Definition: Not productive; useless; fruitless.
Example sentence: Trying to find ideas is the hardest part of my job. You'd think it would be the most fun. Just sitting around reading whatever I want, going to cafes and libraries. But I always feel so unproductive. I think I was raised too well by my parents.
Ineffective
Part of speech: adjective
Definition: not having the desired effect; ineffectuallacking in ability; incompetent or inadequate
Example sentence: I succeeded at venture capital because, for years, I rarely thought about or spent time on anything else. Anything less than that unmitigated full commitment leaves me feeling frustrated and ineffective.