“ours” baby in a blended family

After being married to my husband for 3 years we are finally getting an “ours” baby. We each have a daughter from our previous marriages. My little girl is 8 and his Is 7 1/2. We are both so excited to add another little person to our family. However, over the past few months I’ve had a lot of worries. What if the girls don’t like their new sibling? What if I love this baby more than I love my step daughter? What if my biological daughter feels that she has been replaced? I’m worried sick. I have a cousin who recently told me that she loves her “ours” baby more than she loves her kids from her previous marriage because she loves her new husband more than her older kids’ father (obviously). But now I’m terrified, what if I love this new baby more than i love my daughter? What if the kids resent the baby? What if my husband doesn’t pay attention to my biological daughter anymore? I literally have nightmares every night. I’m one worried mama who just wants make sure all 3 kids get an equal amount of love and attention from both us 😪 I just want to be one big happy family 😭 oh and by the way we each have full custody of our daughters so they’re with us all the time :)