I would suggest giving a bit general statements and not sound specific.
6 months into the job, I found myself at a crossroads as there was not much prospect as what I was doing was very different to the job offered to me, I tried speaking to my manager but (he/she) could not promise me any affirmative actions.
I know I would have excelled as a <job role> given the skill sets I have.
But this is imo.