I assume you aren't married - is the house in both your names?
If you are primary carer, then you should be the one to stay, purely because the most important thing is stability and continuity for the children. If it came to it, a judge would support YOU staying and him going, so that the children's home lives were minimally disrupted, while the necessary practicalities of a split were undertaken, e.g. selling home.
Let me guess - You get them up, give them breakfast, get up in the night with them if ill, you're the one putting on a wash for school uniform unexpectedly at 11pm so that the next day is sorted, you're the one putting them to bed, making sure teeth are brushed and pyjamas sorted, yes?
And he thinks you should be the one to move out? Right.
You've both contributed equally to the family life and home you have now. It's not about who has the greater right out of the two of you to stay - it's about the dc.
His stance shows him to be putting himself above his children.
Don't go anywhere. First thing tomorrow, find a local family solicitor and ask for a free half hour advice. Secondly, contact Women's Aid - espeically if he is trying to threaten or bully you to leave immediately.
Do not leave AT ALL without your children.
Do you have family nearby who can come over for support?