I am 16 weeks pregnant. I am diagnosed with Gestational Diabetes and schedule to meet the doctor next week

This is my first pregnancy and I am really stressed and worried. I got afp test results yesterday and the doctor said that the test results screens positive for Down syndrome. I am very tensed and scared. Doctor said that afp test was just a screening test and even if we get positive for Down syndrome, she said that the baby might be healthy and normal and we can know it only after few other tests.

I am really emotionally depressed now, does anyone have any advices on what to do?