How do you keep communication between parents easy?

[icanbreathagain]

Maybe not the best title but myself and stbex live separately now and txt and call to communicate about the kids and the divorce and finance settlement. It can make me mad at time when there's a long back and forth in the txt. So my question is how do you make communication work for you?

It's been impossible for me and my stbx wife.
One minute she is civil and asking for money for my daughter to go on a school trip the next minute she just turns nasty because she wants her own way over everything so I get the horrible texts. Collect this that or the other from the house asap or else type thing and just crap like that.
We just can't agree financial stuff because she earns much more than me but won't even give me 50/50 equity on the house of about £23000.
On top of that her solicitor has told me I must pay for the whole divorce including her divorce petition which I said at the time was lies. So far that is £1800 to her solicitor which my solicitor say is astronomical but there is nothing she can do plus my own solicitor and all her costs.