Check if the water that you are currently using at home is not salty; e.g. well water.
What products do you currently use for your hair? Do they have silicons that weigh down your hair? How often do you use them before washing them out? Product build up leads to dry dull hair.
How often do you moisturise your hair and what do you use? Neglecting or over using moisturisers can weigh down hair and make it mattified (your hair reduce its shine or oiliness).
What's the solution?
Make sure that you wash your hair with non salty water (Hakikisha maji unayotumia hayana chumvi).
Make sure you use sulfate free clarifying shampoo every 2 weeks or 4 weeks.
Co-wash every week (this is a creamy wash conditioner or leave in conditioner) to maintain moisture.
Use a detangler to untangle. After washing you can interchange it with a co-wash conditioner.
Seal your hair after washing with a light oil example Argan oil, Extra Virgin Olive oil, Jojoba oil, avocado oil etc.
If Oils are too heavy, seal moisture with a leave in conditioner or styling milk.
When sleeping at night, pineapple your hair with a fabric wrapped ponytail holder or satin scrunchie, then secure with a silk or satin scarf and/or sleep on a satin pillowcase, this helps a great deal with moisture.
Deep treat your hair every 2 weeks, once moisture is restored switch to every month. You can use hot oil treatment as well.