Overall cholesterol is good. triglycerides are close to 300 (296) what does this mean for diabetes control? what causes this to rise, it was fine

Elevated tri's: A couple of things cause triglycerides to rise like having eaten a fatty meal prior to testing, suboptimally controlled diabetes, hypothyroidism, excessive alcohol intake and too much protein in your urine(so called nephrotic syndrome). For you it sounds like suboptimally controlled diabetes may be the culprit. Hope this helps.

Fats and inactivity.: Saturated & trans fats in the diet can tend to make your triglycerides rise, while monounsaturated and polyunsaturated fats can lower them. Inactivity also allows the triglycerides to rise. While high triglycerides don't cause diabetes, increases in the triglycerides can parallel increases in the blood sugar.