Hey there.
I have your same problem, I'm deaf on my left ear, been like that my whole life. I really feel for you and know what you're going through.
I stumbled on this post searching for the same solution.. I'm looking for something at OS level so it's not restricted to the player of choice.
What I can tell you, if it can help you, that exist some "voip" headphones that are stereo but for a single ear.
I have an old one at home wich is overused (guess why) which clips to your ear (can pick left or right just turning the clip) and it has a little mic in front. It has both green and pink jacks (audio and mic) but usually I just plug the green one and forget
about the other.
It's got almost broken because I carry it around and use it with my portable devices too. I look kind of weird going around with a voip set on my ear but hey, let them have fun at my disability.
Anyway, if you find any good solution, let me know.