Well, I guess the time of this post indicates where my head is atm!
Definitely up for some hand holding 
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See a solicitor pronto - I suspect in your situation you may be able to stay in the house until the DCs are grown up at least. I would imagine your issue will more likely be getting him out.
Next thing (assuming you're in the UK?) go to entitled to or turntous.co.uk and see if you will be entitled to any tax credits, and the CSA (now Child Maintenance Service) to get an idea of your financial situation.
I would also suggest putting together a lockable filing box with all relevant financial paperwork, passports, birth & marriage certificates for you and the DC, NHS/National Insurance cards (and make sure you have a note of your H's too), and a memory stick with any important photos, computer docs on. Stash it somewhere (boot of your car), maybe even with a small suitcase of clothes for you & DC, basic toiletries, spare mobile & credit card. If he does get nasty at any point you can gather the kids up and go, knowing you have your basic needs covered until you can take legal action to remove him and gain access to your home again.
Keep a record of all the incidences of his unreasonable behaviour - maybe use a memo app on mobile or tablet if you have one and it's secure?
My H was never physically violent (he did threaten me indirectly on a few occasions) but was very aggressive and intimidating in his manner - shouty, sweary, prone to sulking, stonewalling and mood swings, would throw things about under the guise of 'tidying up', slam doors etc
He is now struggling to understand how it reached a point where both DD and I are afraid of him when he never physically hurt us. He has agreed to seek counselling to help him manage his feelings/stress levels and improve his communication skills, after which I've said I may be willing to consider couples counselling/family therapy but have made it very clear that I cannot make promises for the future.
We spent the afternoon together with DD yesterday and it was fairly pleasant under the circumstances. He seems genuinely heartbroken and desperate to make things work but a tiny person in the back of my head is going 
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We've been at my parents' for 3/4 days now. My mum who has been very supportive thus far and never had a great relationship with him, now feels sorry for him and seems horrified that in such a short space of time I have moved out a lot of our stuff, sorted out a tax credits application and made arrangements to write a Will. I have had to point bout to her that although it would be ideal if we could get back on track, there's no point assuming it will happen and then ending up down shit creek in 6 months time if he reverts to type.
My 11yo DD is doing incredibly well, if somewhat clingy. She said tonne the night we left, "Every time I feel sad I think of my favourite quote - without change there would be no butterflies".
Sounds like a pretty good mantra to me!