Due baby number 2 in 8 days and worrying!!

I'm worrying about coping with 2 kids! I have a friend who has 2 kids with a similar age gap to mine, 2years, and she struggles so much! Her eldest no longer sleeps through the night like he used to and her youngest has never slept well! She feels like she broken and it's effecting her marriage!

My little girl (she's 2) has always been a good girl) always slept right through and has a 2 hour nap in the day. She was such a good baby aswell!

I worry that this new baby will waked her up in the night and it'll be chaos! I worry that she will stop sleeping through and become naughty!

My biggest worry is going out to doctors etc with both of them and not being able to cope!

Please someone tell me it might not be awful and it could be wonderful!!