Suggest Diet To Bring Down The Cholesterol Count

My cholesterol count is 9.1. Three months ago it was 8.3 so I went on a diet educating my self as to what foods I should and should not eat to help bring down this level. I managed to loose 30lb and was feeling so much better in myself. I had another blood count done last week and was absolutely gutted to find it had gone up to 9.3. Why should this happen, I m doing every thing I should with a healthy new life style. It just doesn t make sense. I have now been put on 20mg Statins a day. Could there be another underlying health problem that s causing this?