Oh OSJ, Im so sorry to hear this. DP is still here, and we had a bad row last night. Its the inbetween bit thats horrible - like you say, sorting out finances, what do you tell children etc.
Keep talking to us here - someone is bound to be able to help with advice.
Whereabouts on Cornwall are you? Im near Tavistock, so parts of Cornwall are possible if you want to meet up.