I along with many others associate you with probably setting the bar when it comes to writing different cultures/races with respect and diversity. Someone has commented on one of my online stories, saying that describing the male dark skinned character as

That’s very kind of you to say, thank you! And the fact that you apologized to the reader, and are now seeking advice and education, is a great sign.

Without having read either the story or the reader’s comment myself, one thing I can say for sure is that “hulking” is not the best word choice in this situation. It has a lot of negative connotations. You want to portray the character as a gentle giant and not a brute, but the truth is, when I hear the word “hulking”, I do associate that with qualities like brutish, menacing, clumsy, lumbering, etc. I can’t think of any positive connotations for the word at all. So I’d certainly suggest removing it!

As for more specific advice, however, it’s important to remember that I’m still a white author. Advice on writing characters of color ideally comes from authors of color! There’s a great resource right here on Tumblr: Writing With Color. Check out their FAQ and their Navigation page for some very in-depth discussions on this subject. You can also ask them questions directly, but be sure that you read their guidelines first, because they do get a ton of asks.

Best of luck, and happy writing!