Hey April I went through this years ago as a single dad with two kids. My ex, a jw refused to pay despite working and having a working partner. The dramas we went through! Looking back, who came out the worst? The kids. When I realised this, I made a fundamental shift in my expectations and attitude.
My advice is continue with legal action but don't expect anything from him. His loss is huge. He will never know the honour of loving and teaching your child and the unconditional love that comes in return, unless he realises his responsibilities.
May I also say that my expartner and I are truly friends now and that our children have grown up(23 and 20)happy and healthy. This only because we both started acting like adults and responsible parents
P.S .G'Day Deb if you read this!