Iam pregnant and don't know what to do

Iam a single mom to a beautiful child.

My boy friend and i fell pregnant a month ago and i found out i was pregnant with twins. Well he vanished right after that. Sending me money for a termination.

I want to keep these children but i cannot afford it by myself at all. A single mom with 3 kids and no help. Right now me and my son have a really good life. I am sick with anxiety as to what to do. Any advice?