Twin pregnancy and unsupportive partner.

Okay so I've just found out I'm pregnant, have 3 already all under the age of 7, I went for the first ultrasound yesterday to determined how far along and found out there is two, both only 5 weeks. I'm terrified as I'm not sure I could handle having another one let alone two!
I don't really want to terminate but it's not something I haven't thought about. I don't really have any family close and my partner isn't very supportive, my plan for this year was too eventually leave him as he does verbally abuses me, puts me down when he gets into his moods and often doesn't help with the kids unless I ask him, even then he makes things worse cause he doesn't know how to respectfully deal with them, but since talking to a psychologist I've come to see its not normal not should I have to put up with it, so before the pregnancy I was starting to put a plan together to leave but this changes that plan. I honestly don't know what I'm looking for, maybe advice on if someone's been in similar situations or what to expect if I go through with a twin pregnancy as I don't know anyone close that has had twins....