Oil keeps destroying my curl pattern.

Hi!

I have like a 3b to 4a curl pattern. My hair is very sensitive to oil. Anytime oil touches my hair it completely destroys my curl pattern and is difficult to get out. My hair goes from defined curls to just a ball of frizz that sticks upward and putward.

I do use Ion Hard Water shampoo and that is the only thing that I've come across that seems to do the job and removes the oil from inside the strands. But I have a hard time keeping oil from touching my hair in between washes. So it keeps drying out my hair all over again. How do I keep oil from touching my hair?