He's threatening me if I don't abort.

A little background, I was originally born in Colombia. I came to The States in my teenager years. After my visa expired I've been able to stay in the country with a work permit that it only allows me to stay within the USA territory and if I leave the country for I cannot come back. I told my now ex boyfriend about my 6 week pregnancy and he told me that I have 2 options, have the baby and live a life of misery or "fix it" and prevent him from getting me and my sister deported. I told him he couldn't do that because I haven't done anything wrong and I'm not asking him to step up as a father. I just told him because he's the father and I thought he deserved to know. He said "I have a lot of family, anyone can take you to the Mexican Border" he said he will first start with my sister and then me. He also told me not to forget about my son, I have an 8 year old from my previous relationship and he was born here but my ex told me that he'll make sure my son is taking away by the system while I'm being deported. My mind it's just to weak to get over an abortion, that would mark me until the rest of my life and I wouldn't forgive myself if my sister is taken back to our country. He said that I have until Monday to figure my shit out so he can take me to get the abortion or else he'll start making phone calls. We've been together for 5 years and I had no idea this would be the reaction. I don't know who this guy is... I'm sooo scared he will do something even if I end the pregnancy. I hate him so much... I'm sooo scared... why God doesn't just let me miscarriage instead?? I have no more family here, my sister is the only family I have. I can't kill my baby and I can't let my only family suffer for my mistakes.