What's ahead for me???

I seperated / left my partner of 20+yr's over a year ago, weve kept it out of the courts and ive been paying an agreed amount for maintenance. My kids have been staying with me every other weekend & i have them on a weekday evening (once a week also) but drop them back to her after dinner. I live alone and am struggling with costs so have to look for alternative accomadation which is in the form of a house share, meaning the children are now unable to stay over at the weekend. Im hopeing this will be short term to allow me to save enough to get a deposit to buy a place in say 2yr's.
The Ex Mrs is not happy although im offering to up the maintenance stated on on the Gov calulator for Nill nights - Im intending on seeing my kids as much as previous but without the overnigh stays, dropping them back with her each evening. Shes now taking me to the CMS & its getting ugly. Im looking long term to get a stable place for us all but she sees it like im shirking my responsabilities! which im not. Am i now likly to pay more? Or will they do better than the Gov calculator and actually look into my outgoings, debt & earnings rather than just my wage, nights they stay and number of children?

Is there a family home that is owned? If so, it needs to be sold or she needs to buy you out. It is not appropriate for you to be in a house share whilst she is living in the FMH.

Ignore all the people saying she will be able to stay there until the children are 18. It's total cobblers these days.

What are you paying for now?
You use the term partner. Presumably not a civil partnership or marriage?

We didn't own but rented privately, I left so there was minimal disruption for the children. I found a new rental but I cant afford hence having to now move again into a house share. I'm not entitled to benefits and cant afford a deposit to buy a property without taking this step back to save.

If she chooses to use CMS then the assessed amount is the amount you have to pay.
However that is all you have to pay. If you are currently paying her bills or rent then stop doing so.

I understand I would have to pay the CMS the assessed amount, but what i would like to know is: do they take into account more the Gov maintenance calculator? As in would they look at my outgoings? Not just my annual wage, number of kids & nights stayed over. Whilst my kids currently stay some evenings this may not be the case going forward for a short term.

No they don’t take into account outgoings.
It’s just based on income.