Cholesterol comes not only from our diet habits.
There are other risks factors that are not to be overlooked in hypercholesterolemia.
There are factors in which we can have an influence: smoking, alcohol consumption, physical exercise, stress … and others where we can’t do anything: a family history of haert disease, ethnicity or age.
Anyway, hypercholesterolemia can only be measured by a blood test. It is so better to ask a medical advice before changing radically your habits.