You’ve caught his character brilliantly, and that’s the ‘difficult’ part.
But your ‘photography’ fails on a few fronts. Unfortunately it’s OoF, the neckline on the sweater is sharper than the eyes. As a portrait photographer that’s rule no1.
Then as has been mentioned, the background is distracting, including the broken first rule of landscape, you’ve included a dominant colour that’s not your subject.
Thirdly, as above, the person in the catchlight is slightly distracting.
So, you’ve got the difficult part right, now to work on the easily fixed photography mistakes.