I find it very disturbing that in the same sentence that you state you are still in a relationship with this man you also state that he is threatening to take your child and take legal action against you -- sounds like time to seriously re-evaluate your relationship. First, though, it is time for you to file a petition for full legal custody of your child --- NOW! You and the father each have equal right to seek custody of your child -- better to file your own petition and not be on the defensive side of the case that seems ineveitable for you. As he is already expressing his intent to file for the child's custody I urge you to beat him to the punch and file today. If you cannot afford a lawyer contact Legal Aid or the clerk of the court to obtain a "child custody packet" -- they contain all the papers and instructions for completing and filing the papers, the one advantage of Legal Aid over clerk of the court is that Legal Aid workers are able to advise you and the clerk workers will not be able to do anything but hand you the papers. However, I would urge you not to go this alone -- remember he is already threatening with a lawyer of his own -- instead try contacting local family law attorneys .... most give free initial consultations and many are willing to work out a payment plan...so many people never try to get representation because they think they can't afford it, but in this case I would suggest you think of it as you can't afford NOT to have an attorney. As you are living with your parent's I would suggest discussing with them if they would be able to assist you with the financial side of this. I know what you are going through - I filed (and won) my own custody case four years ago...total cost was only $275.00 and it wasn't as horrible as I had imagined. Most of all, you need to do what is best for this child -- and from your post it would seem that the best for now would be for you to secure the child's future by obtaining a legal custody order to avoid the heartache not having one could cause later. And do take a few minutes to think over your relationship....doesn't sound like a great one and it is never in the best interest of a child to stay together just for them and let them have two miserable parents.
Good luck and God Bless