At the very least OP get your injuries documented either with GP or Police while they are fresh.
Your job would have to give you leave under the circumstances, you would not lose your job, GP can sign you off sick. If they did try to sack you, you could get an employment lawyer and do them for unfair dismissal and they would end up owing you compensation.
He cannot lie about documented, reported injuries.
How old are DC, old enough to understand if you sit them down and explain frankly what he has done? Would they want to stay with a man who has assaulted their mother?
Isn't he making your life hell already? At least if you leave it will be hard, but things will start to get better.
He cannot fabricate what isn't there, the Police will believe you not him, he is clinically depressed and not in his right mind.
You will not even lose your home, you and the children would stay and he would be out with an injunction against him to not to come near you/house again. Get legal advice now.