How to Lower genetically high cholesterol?

I have genetically high cholesterol. it’s near 300 I think. I’ve dropped soda, fast food, fried food, beef, ham, dessert, and candy and snack food altogether from my diet but my cholesterol levels only dropped 10 points! I work out almost everyday and bike to work. I should probably start medication but I’ve heard about the damage that can cause and I’m not ready to get on to any hard meds. I’m only 22! Any thoughts, guys? I’d appreciate some help.