Oh my, I 'm so sorry you are having such a tough time
I think it's a decision only you can make based on how you think you can cope with all of this. Being newly separated, potentially poorly baby on the way, and 4 children to care for, places you on a huge emotional roller coaster.
My husband was diagnosed with advanced cancer in 2011 when we were in Brisbane, and it was a complete nightmare! When life throws us these horrid curve balls decision making is never easy.
Good luck with any decision you make xx