Should I Be Concerned...?

I have seen my dermatologist last week and was told that my cholesterol level was way too high (7.5!!!!). She suggested I carry on with 30mg for another month.  I thought my dose should be higher on my 2nd month but it did not happen:( I have no idea how did I get cholesterol level that high?!!! I mean I am on a diet where I do not eat fatty foods, dairy products etc. I eat fish, fruit and veg....how can this 7.5 happened?!!! With this 7.5 it looks like I eat Macdonalds all day and drink butter. I might as well forget about diet and start eating all sort of rubbish as it does not seem to work anyway!!!((
My skin is dry, no active acne and no other side effects.
Is there light at the end of the tunnel?