Still so nervous

I had a missed miscarriage 3 years ago. I’m pregnant again and i was so scared at every doctors appointment I went to.. I kept telling myself that I couldn’t wait til I made it to the 2nd trimester so I could stop worrying. Unfortunately it hasn’t stopped. They did one genetic test to test for trisomy 13, 18, and 21. I was scared shitless til I got those results. Everything was fine. At the next appointment they tested for Spina Bifida... everything turned out fine but again I was scared beyond relief. Now I have my anatomy scan in a week and the closer it gets to my appointment, the more I freak out.. baby daddy bailed on me so I feel so alone through all of this... what if I go to my appointment and the baby only has 2 chambers in his heart? Or what if he’s missing and hand or something? I’m so scared and I just wish this feeling would go away...