You will be fine! My 2 youngest ones are little over a year apart, the pregnancy with dd was tough, especially because I had SPD (due to the short gap inbetween pregnancies) and I was also petrified of giving birth since ds2's birth was still so vivid in my head. It all worked out well, I got an epidural (never even considered it for my boys, will defintiely have one again next time ;)
The first months were hard. Ds2 was a toddler and a wild one at that. He went through a rough patch after dd was born, hitting other children, taking everything away from them, it was awful. The hardest thing for me after birth was the breastfeeding part - I struggled to find the time to let my dd drink in peace and long enough for her to get enough and me to empty my breast. This resulted in mastitis (twice in the first 10 weeks, but I have a tendendy to get them anyway). I hope you can afford someone to come help you with the household, that would be a great help. But if not, who cares if your house is messy for some months, honestly?
My kids are now like twins, they share a bedroom for now as well. They are so adjusted to another, its great. Its the reason I wanted another short age gap this time, 21 months, I wanted to wait 12 months before falling pg again due to the SPD (and so far it hasnt come back, yay!).
I think your husbands reaction is totally ok, actually. He has to go away, he is under pressure, he worries about his family not coping. Fair enough! I am glad he came aroudn though. Abortion or giving a child up for a adoption, christ, I know my marriage wouldnt survive something like that. Another baby? Ah yeah. Its just the first months that will be chaotic. Take it with humour ;) Congratulations on your pregnancy :)