Hi OP as everybody has said, very lucky escape.
I know it seems daunting now but you can do this and think about you will not have a petulant man child to deal with too. you can spend all your time with your child and just enjoy motherhood.
Once you have had baby, see if you can find some childcare, family members etc if not there are some wonderful creches out there plus with free childcare hours I am sure you can make it work.
Remember you are not alone a lot of us have done it on our own and made it out the other end.
It is frightening and when you hold that baby in your arms for the first time you first thoughts will be "what on earth do i do now". i was so scared I was going to break her, my baby handbook became my best friend.
But you need to get rid of him, set child support with CSA up and make the little boy pay. Do not fall for any crap he might throw your way and please do not think every child needs its father. Mine did fine for 6 years until the perfect father figure for her came a long.
The only thing you need to worry about now is whether or not you are going to stick with gas and air or have an epidural. Take the epidural and dont be a shero! :)