Globetrot - don't worry about coming here at all (easier said than done I know). There are so many of us with children and husbands at work all day, and most of us can relate to the fears that you have. Nowehere in Sinagpore is that far away and before you know it you will have a new network of friends (granted not family) who will be able to help when you feel you need it and they will also be there when you just want a chat. You already have one here - me! (I promise I am not a psycho but I am from London!)
As for having more kids, this is something that I am also worried about. I love my daughter far more than I ever thought possible and I honestly wonder how I would be able to love another just as much? I have three friends who have two kids and I swear they all say that the second one is their favourite as the first one was so alien to them or they had so much trouble and worries with the first one and the second one is so much easier so they can appreciate them more etc.
I also had a bad pregnancy (out of 9 months I think I was only NOT sick for about 2 weeks), not a great birth, child was taken into hospital once born due to illness and to be perfectly honest I am scared of going through that again.
I know I am looking at this from a negative point of view but these are my fears as to why I am still happy with one.