19 weeks, now I have to go for an ECHO :(

I'm so stressed. I'm just going to vent here for a minute. I've posted before about having a high heart rate since I got pregnant. I've had episodes of dizziness to the point of having to sit or I will pass out because my vision goes grey, etc. My OB attributed it to dehydration, but we did an ecg and it came back abnormal. So now she's sending me for further cardiac testing. I realize this is best practice and she's just being safe because I'm also pregnant, but I can't stop worrying. I go for an echo on Monday and then a 24 hour holter on Tuesday, then I see the cardiologist on Thursday. I also have another ultrasound for the baby on Wednesday. I'm starting to feel stressed with all these appointments. I'm only 28 and fairly healthy, don't smoke, rarely drank, etc. But I have a lot of family history of heart issues. I know stressing is worse for the baby, but I'm just so scared I'm hurting him or her. I've passed out pre pregnancy before and all of my ecgs were normal. Same with the holter monitor readings. I'm just starting to get really stressed out and worried. The nurse said if the doctor was immediately concerned she would have sent me to the hospital right away. 😭