I worry about miscarriage so much... any reassurance?

I’m currently 6+4 and I saw an ultrasound at 6+1 and got to see the heartbeat. I’m 18 and I don’t have a history of miscarriage or anything me and my boyfriend did not plan this baby but we both want it badly and I worry SO MUCH everyday I will lose the baby... I have extreme nausea and vomiting and fatigue but I’m almost grateful for it it means the baby is growing... it’s very scary to think there’s a big chance I’ll lose the baby. Also heart rate was 100BPM...