Help Me

Lesbian . New Mom . 4 months old

I was single for 6 years finally got into a relationship with a guy. Started dating , moved in together and then we found out we was pregnant. Been friends with my ex for about 8 years ( female . before him )still in love but not enough to deny or call off our engagement because of her , So lately I've been stressed dealing with our LO, and work and school and housing ... He starts talking to An old his school crush because "I don't show him any attention, I don't spend any time , and there's no communication " .. So now he's talking to him old friend right ... Nooo ! He's making plans and talking to her like she is soon to be his"... I called off the engament but now he's threatening to take my son away from me because " I smoke cigarettes all day and occasionally herbs " .. I spend plenty of time with my son , all the usual mommy things but if dad is around yeah he stays with dad... But now this... I don't know what to do, he's intimidating , over bearing , controlling , abusive (mentally) and (verbally) . . . what to do ? I don't want to lose my son after a long had pregnancy, split from front to back from natural birth, breast feeding for almost 2 months , mastitis from backed up breast milk and killing myself to make sure were okay...

Please give me answers besides a DV shelter ...