Ultrasound measuring behind

Please if someone can just give me some words of encouragement. Just had second ultrasound today and I'm measuring the same as 7 days ago with only gestational sac and yolk sac measuring 5 weeks and 2 days. Doctor told me to prepare for m/c this will be my second one. I had my first m/c last July and can't imagine going through that painful process again. My boyfriend is saying it's life and not as emotional as me. I just don't understand why and if the problem is me. I was adopted and to have my own flesh and blood is so important to me😢