My LDL was 200mg/dl last march I reduced it to 90mg/dl by exercise and meds. Is it certain I will have atheromatous aorta? Heart attack? So scared

You are doing. everything correctly. Diet, exercise and medications have reduced your LDL by over half and into the normal range. Congratulations! You have done everything possible to reduce your risk of cardiovascular disease. Keep it up. Thanks for trusting HealthTap!
Ldl. At your young age it is very unlikely that you have developed significant atherosclerosis even though your ldl cholesterol was 200. I believe that you have caught it early and have taken care of the problem nicely. A treadmill stress test could set your mind at ease about your coronary arteries and an ultrasound of your carotid arteries would show that you have no plaque formation.
Not necessarily. Congratulations on making such an improvement! Being that you're 23 y/o, you probably haven't done too much damage to the heart yet. Best thing you can do is to keep on with the diet and exercise and have regular evaluations by your doctor. Part of cardiovascular disease is genetic in origin - so being vigilant and catching any problems early on - will offer you the best chance of success!