Question about cholesterol lowering crestor?

Today i went to the doctor and was prescribed crestor for my high cholesterol. I am 24 years old. My cholesterol has always been high (over 300) since i was 10. Despite diet and exercise. I am not over weight, I weight 122, 5'4 (not overweight). I believe its hereditary. my total cholesterol was 312. LDL 224, HDL 73 and triglycerides 89. I told my dad and he said i should only take the crestor for 3 weeks and then stop because it can cause liver problems. The doctor did not say that. What should I do.