I'm terrified

It's just now hitting me, I'm going to be a mother. my twins are coming fast. My husband will be leaving for deployment shortly. not to mention I keep thinking about how unhealthy I was as a child and how many times I was lucky my parents got me in when they did. than not to mention all the allergies me and my husband have. all the mental disorders that run in our families. I know a little late to worry about all this, but this pregnancy wasn't planned we we literally said screw it if it happens it happens. we're prepared for them about as well as the average Joe shmoe usually is for kids, but what if I'm not good enough. I love my mom to death, but she was physically and emotionally abusive and my dad was absent mentally and emotionally due to his severe depression. what if I'm like them where I shame them for every fuck up or slam them into a wall every time they spoke up. what if my husband becomes like his father and starts drinking heavily and becomes abusive to me and the girls. I need to stop I'm a little hysterical right now and just need to know if anyone else freaked out this bad before having their first kid/kids.