Clingy baby + new baby

I'm currently 30 weeks pregnant with baby number 5. I'm looking forward to meeting our newest creation but also terrified! The kids I already have are 13, 11, 6 and 11 months. I found out I was 14 weeks pregnant after my husband and i seperated and it was very much a surprise. The issue is my 11 month old is very clingy, even with her dad she just screams until I'm holding her. We've tried everything, she gets hysterical and ends up choking and throwing up. She still wakes up 3 or 4 times a night and has always had feeding issues. The older three are mostly quite good but I'm finding myself stressed, cranky and exhausted every day and I just don't see how I'll be able to fit a whole nother person and their needs in without drowning. Also I'm worried about how my daughter will cope if I have to stay in hospital and while I'm in labour even I really have no one that can look after her...then there's after I get home... I'm hoping someone has some advice or can even just say you've been there and survived.