K.J.
He can never take her from you unless he can prove to a judge that you are an un-fit mother, which is very hard to do. You have a good job and are educating yourself, which to me sounds like you are the opposite of un-fit! Don't worry about that, if he says he is going to try to do that, just know he is only trying to intimidate you. You mention that you are single, so I am assuming you and the father are not married. If so, then the Mother is the natural guardian of the child, you have sole custody. The father has no rights until he establishes his rights through a court order. Which means he has to hire a lawyer and take you to court. Which takes money and a lot of time. Make sure you let him visit her if that is what he wants, even if he's not paying support(I know that sounds hard)but it wouldn't look good on your behalf. No matter what he does or doesn't do, you want to look better than him. Start documenting everything(I use a small calendar)concerning him and your daughter..was he late for a scheduled visit or did he cancel? how long was the visit,did he not change diapers etc..And try to keep conversations via email(for
documentation) What you want to do is have proof of everything in case you end up in front of a judge.
I hope some of this helps. It is a very scary thing when it all starts, but hopefully with time he will give up and be less agressive- that is how it turned out for me, and thankfully I never had to go to court,-knock on wood! Hang in there you are doing great!