I do love characters who cover up anxiety by being pissy and angry instead. Nawee is obviously terrified of making the wrong choice and freezes up with the samples but decides to be angry instead of scared because anger is safer, anger is easier, it's easier to pretend he wants someone else to make the choice rather than admit he doesn't know how to make it on his own. It's safer and easier to blame things on anger than admit that he did something wrong or made a poor choice or felt overwhelmed or got scared. And his anger has been catered to, his anger has always gotten him the results he needs.

Will I ever like a mentaly stable optimistic character?

I want to see Nawee's dad die 💀 ooof,