First of all you need to find out if this is really true. Why does he want to leave you? Is he having an affair. If there are problems in the marriage then it might be advisable to seek the help of a marriage counsellor. However, the most important starting point is to talk and discuss each other's feelings.
If he has already stated that he is going to leave you, then it is advisable to get the help of lawyer to find out what your rights are, what his rights and responsibilities are (both towards you and any children you have). Also all aspects of your family life will need to be decided (financial, custody of children, joint assets, the family home, coping emotionally with the split, preparing the children to cope etc). That in itself will take alot of emotional energy.
Then you can think of re-building your life separately from him.
People tend to say things in anger. Since your husband is abusive you should consider going to a Woman's Abuse House to find help and learn tools to cope. No one has the right to abuse the other. Your relationship is toxic and you are in control of your life and not your husband. To tell him you are going to kill him is a serious accusation and when you get to this point it's time for you to leave this abusive relationship.
We don't know your husband or his girlfriend, nor what a "cope" is in any sense that a person could be one.
I'm not quite sure of your situation but you don't and you shouldn't. Leave that guy as soon as possible. It's his mess his problem and not your baggage.
You leave.
the best way is through a psychologist
How they cope at seashore depends on what is going on at the time. If a hurricane is coming then a person will cope by boarding up their windows and taking shelter.
That would depend on what sort of relationship they had beforehand.
You cope by finding another guy to like who is FREE.
Keep yourself busy. Hang out with friends. Also drink (responsibly).
The way that a wife could cope with it is 1.talking to the husband 2.calling someone in front of your husband sweetie 3.talk to a therapist 4.find out who he called sweetie and we he called her sweetie. and 5.beat the crap out of him with a golf club or any blunt object.
All people will make you jealous at one point or another so done let it affect you. Try to cope with it and understand what is going on. Good Luck
Copeing with unemployment is going to be hard because employment is what helps you live too get money and make a living but, you can cope I would suggest seeing a counsler.