Type 4 hair holds more protein due to its texture. You need to find a protein/moisture balance. Try to find samples or swap a light protein conditioner like Aubrey organics GBP (or GPB). It gives you a shot of protein AND moisture. Just be careful not to overload on protein or moisture. Also don't forget the straight ends of your hair are the oldest and most fragile. Your ends need moisture more than anything else. You need to get the Science of Blackhair it will explain all of this and even suggest products. Good luck!!