Terrified and sad about it

I'm excited for this baby, my first, but I'm currently in a phase of equally terrified. It's just such new territory, what if I'm a bad parent? What if it pulls my so and I apart? What if I can't do it? Or worse what if I regret choosing motherhood? And then I feel awful for being so scared but it's hard to imagine how different life will be. Anyone else feeling like this? Or for those who are on #2+ can you describe what it was like making that initial transition into motherhood after the birth?