Hi…Joao …
I don’t know how close you are trying to get to the refference that you are working from…great refference by the way…but in the refference, his chin is much narrower , and for that matter so is his whole face…try to imagine him without the wrinkles, and measure the distances of the inner forms,…lips, eyes, cheek bones ect. to the outter edges of his face.
Also in the refference, the muscles across his brow are working and tense, creating a big part of his expression and character. His nose is really bulbus at it’s end…many years of drinking no dought.
His ears are much bigger in the refference…a major part of his character.
The end of the lip edges on the left side of your refference is angled down much more than on the right side…adding to his expression.
You might also get that raised collar line in there also…only comes with someone of his age…
The most important part of doing a realistic portrait, is to get the major facial muscle forms and expression that creates the character down first…head width, length ect. all of the wrinkles are just superficsal elements, and without the major forms in place first, will leave you disapointed as you stated that you were.
Hope that is of some help to you…Keep going, you deffenitly picked a tough one…for sure…but as long as you learn something from it, that’s what really matters…

TAKE CARE
Glenn