Thanks everyone
Police just left, friend gone home & DD in bed.
I've made a statement and said I will press charges , they said they would be prosecuting regardless of my statement.
it's all a bit weird and happened so fast... he text then rang me earlier tonight crying/upset asked if he could come to mine (5 miles apart).
I asked if he'd been drinking, he said no so I said Ok pop round, regretted it instantly as he only does all this when he's drunk/depressed so I sort've guessed he was lying tonight 
He came in swearing and started throwing things around, screaming at me " you think you're f*king perfect don't you?" I didnt reply and he attacked me, grabbed my hair and punched me repeatedly in the face, then threatened to kill me, emptied a bottle of wine over me put his hand over my mouth to stop me screaming and raised the bottle to hit me.
I bit him and screamed the boys are upstairs and I was struggling to sit up/get up, managed to push/hit him then told him to get out of my house.
He left and we (police friends DD etc) cant find the bottle anywhere, not sure why he ran off with it 
he left his glasses.
It transpires that on his drive to mine he's had a RTA and failed to stop, other driver has rung police and given number plate and description so police are at Ex's house looking for him when I ring to say he's hit me and driven off drunk.
There being only 1 road between his and mine they simply met him on it, breathalysed him and arrested him.
So he's in a cell till late tomorrow and I was meant to be taking all my children on a special Day out in the morning, now can't go.
Got to have more photos taken at police station.
No idea what to do
Police said I'm high risk on their DV tick-list
and
If he's charged he won't be allowed to see any of the children or come near any of us
how do I tell my 2 DS's all of this? What the fuck do I say?????