doormat, you will need to practice the "grey rock" attitude.
there is a cycle of behaviour that he will put you through:
he will turn it all on you, he will promise to change, he will buy flowers, he will cry, he will then say you are mad, nuts, incapable, he will threaten to take the Dc, he will do all of this.
You must remain sceptically silent,
the best response is, "its not working for me", & repeat.
Do not try & justify yourself, explain, reason, or cry.
just say its over & not a day too soon.
It will be tough, you never wanted it to be this way, you don't want to be a single parent, you love the person he used to be.
But PEACE is in front of you, all the hurt, dread & anger is soon in the past. Please do this. Do not back down. re photos, tell him you have reported this to the police?
Beware of him getting violent when he realises this is for real.