What to expect

Hi 

I have my first hearing in september for finaces

currently my Ex is living in the family home with my 3 kids 2 adults 19 and 23 both working and a 17 year old at college and working part time

she got me forced out in December 2019 when called police accused me of DA weeks after I said we need a divorce and sell and split equity 

anyway 

since 2019 I payed the mortgage as its in my name only it was £800 pm 

she agreed at first to pay 1/2 and didn't want child support 

after a month she applied to Csa they said I must pay £400 pm 
I suggested why dont I just pay the mortgage then and dont pay csa 

she said no

so every month £800 mortgage and £400 csa left my bank then she paid me £400 towards mortgage 

that lasted 2 months 

then she stopped paying her 1/2 

so I said I wont pay the £400 csa as I am paying the £800 mortgage 

this went on a whiile and then one day I noticed that the Csa had taked £4k from my business account and given it to her

they wouldn't take the fact I was paying the mortgage since 2019 and was living on friends sofas 

they nust said she isnt on mortgage and kept saying that I am going to benefit when it sells 

When mortgage intest rated went up the mortgage went to £1100 pm I told her that she needs to call Csa off and pay some toward the mortgage or I will defult as can't afford to pay it as my work has been effected massively since spit and I live away from the area my business is

so for the last year she called Csa off and pays £350 pm Im paying £800

she works plus gets £400 pm off my 23 year old and £250 pm of my 19 year old 

can someone tell me if this is right

am I been mugged off

she seems to think I shoukd be paying this 

I dont think I shoukd pay anything towards the mortgage as I dont live there all I am responsible for is my 17 year old and if was paying Csa would not be more than £200 pm 

I am just wondering what a judge will say to do 

will they say sell and solit 50/50 

theres £300k equity in house and £170k left on mortgage 

or will they say sell when youngest is 18 

if so whats fair as be paying £800pm is killing me some months I am literally only nust making enough to pay it I am living with my Dad who is basically supporting me is embarrassing at 44 I am living this way

any help appreciated guys sorry for the long essay