Anxiety and nightmares 😢

I have been having really vivid dreams my whole pregnancy, I get them every time I've been pregnant (I had 2 miscarriages this year, both in first trimester, and this pregnancy is the furthest I've made it). I could handle the dreams waking me up but the last two weeks the dreams have been nightmares where I either miscarry, I get told there is something wrong with the baby or they're just plain horrifying ones where I'm bleeding out.... I know I'm probably having the dreams because of my past experiences and I'm anxious about the 20 week scan on Monday but does anyone have any tips on how I can make them stop? They're really getting me down 😢