I need help with my dry rough curly brittle hair

My hair is so dry curly frizzy and rough. I have Greek and Italian decent and Irish. My brother has super nice model hair and It’s so flows. I use all the right products and use argon oil after I shower to make it better but it still doesn’t work. My nrkthers make fun of my hair for a Brillo pad and I use everything and she’s moisture products and I deep condition 1-2 a week and I’ll show u my hair. Please I want to have advice before I try to get a keratin treatment


If you blowdried it with a round brush it would be smooth.