Individual iguanas have many different personality types. Yours might be naturally stand-offish. Even so, his personality is still within the norms for iguanas.
You might get some new ideas from this PDF article:
If there is some error in his habitat, heating, food, etc., that could explain his grouchy personality.
Henry Lizardlover, a man who provided iguanas for Hollywood castings, says he never had to deal with unfriendly iguanas, by doing a trick. He gathered a dozen or so young iguanas together on a floor, and carefully watches them. The ones who didn't flinch or run away from him, who seemed relaxed in his presence and at his handling, Henry picks those to work with. Interestingly, those same qualities are often taught as being signs of being sick, and it's often advised to pass these individuals up when searching for a pet iguana in a crowd of them, such as at Petco.
The GIS iguana care articles don't give nearly enough information that you need. Be open to revising any preconceived opinion that you find strong evidence may possibly be off-center.
15 or 20 years ago it was widely accepted that any iguana can be tamed. I'm not so sure of that anymore. But I have converted more than several really nasty adult igs.
Do that reading, the whole thing, and think about what you find there.
Also, explain what putting your hands in his cage and picking him up is like. I need to know exactly the moves you make, and his reactions to them.
BTW, in my taming and rehab work, I decided to treat all tail whips with indifference, not showing any reaction to them at all. I sort of put them in the category of sneezes, which are involuntary. That way he won't see any reaction from you, and is more likely to give up whipping. But always protect your face. Do not get whipped across your eyes.
I'd like to hear from you again.