Already?

I think he made up that fever lol maybe because he realized Tei only cares for him when he needs care & protection

I think the fever is due to Shuraka being in foreign land. In ch 3, he explains to Tei that the person who has the eye to Natam are not allowed to travel to foreign land. Their blood will behave violently or might bring disaster. The gold blood from his nose may also be due to this.