Why is my LDL cholesterol so high?

For the past 4-5 years I have had high cholesterol (over 200, roughly 208) and my HDL was low (under 40) and my LDL was about 140 while my triglycerides consistently hovered over 200, sometimes 250 and even a remarkable 350. My diet used to be high carbohydrates (pasta, bread, sometimes high saturated fat. The last blood report which was a year from today, showed my triglycerides at 280 while my cholesterol was 213. Obviously drastic changes had to be made, I am only 23 years old. I'm 5'8, 23, male, mostly vegetarian, weigh about 150 lbs now. For the past 4 months I've been working out 3 days a week and playing basketball 6 days a week (or treadmill). My diet has also changed. A lot lower saturated fats, more fruits, more vegetables, a LOT less bread, pizza and pasta. If i eat chicken it's grilled. I don't eat cheese often nor do I eat butter or margarine. I've increased protein amounts for the day and decreased carbs and fat. I've also reduced the amount of food I have been eating and it shows, I lost about 5 pounds in these months (of fat) and put on some muscle. My HDL this time was good, 47. My LDL came out to 141 and my triglycerides were 101 (which is getting better but still not where I would like it to be). I've changed from white to whole grain (even though whole grain tastes like cardboard and don't let anyone tell you otherwise). The only cereal I eat is honey nut cheerios as of late and I've changed from taco bell to chipotle (burrito bowl without sour cream or cheese but with grilled chicken, once a week). Can anyone please explain if there is much more I can do? I've spent entirely way too much time on this and I cannot for the life of me get my LDL to go down. (Should I begin taking fish oil pills daily ) Thanks in advance.