Newsflash. You will not find a lens to shoot every type of portrait, in every type if scenario. Buy an 85mm or longer for headshots, but then try and take a full length portrait with it in a small studio, or a family portrait indoors, good luck.
The thing is, you've said categorically don't use a 50mm lens for portraits, you stated it, and that's complete *****e. What you mean is don't take headshots with a 50mm lens if you don't want distortion. But then again, the flattering distortion of a long Tele lens is considered aesthetically pleasing by many. So either way you're wrong. There's nothing wrong with distortion if you consider it, and use it to your advantage.
Evidently you don't know how to do this, as you have proven, distortion has negatively effected your images due to your uneducated lens choice for the purpose.
And that's coming from me....imagine what a "proper photographer" would say.