Needing advice for a custody modification case...?

In the first hearing I had for custody I had an inexperienced lawyer and a new judge that literally ate chips and drank soda while the case was being presented (incidentally, he's en route to being disbarred) and ended up with partial custody during school breaks (the kids are living in NJ with mom.) Since they have left, my oldest son has developed heart problems due to anxiety, gained an enormous amount of weight and upon return from visits with me has panic attacks and has problems focusing without sweaty palms and pacing. During these times, mom becomes irritated and nasty towards him and will send him to his room and tell him to cry into his pillow so "no one else has to suffer hearing how upset he is" all while belittling my character and saying awful things about me and my wife to him, and recently the awful things are being said about HIM as well due to his relationship with his step mom. While this is happening, my youngest son is being alienated from me while he is under his mothers supervision. I say this because he very rarely gets on the phone with me, and when he does, it happens to be while his mom is out of the house. She has also trained him to eavesdrop on his brother and when he hears his brother speak to me about something the mom doesn't want me to know, my oldest son gets in trouble. She has had my oldest son lie to me about staying home alone after school with his brother everyday and when I have tried to involve DYFS, they have taken her word that the kids are going to after care and the case has been closed twice without so much as a phone call to let me know what is going on. I found out she was having my son lie to me when he was here for his last spring break, during which time he told me he was pulled out of gym cl and recess because of a doctors exam from December 2008 where it was recommended he see a cardiologist. I was told by him every week that his mom was taking him to the cardiologist "this week sometime" which went on for over a month. I spoke to the school nurse who told me the mom had been contacted several times about the issue and the school themselves were considering calling DYFS. He was finally taken to the doctor for his heart yesterday, a mere 17 months after his diagnosis. I have already filed for a new hearing, and at this point am waiting for her to be served her paperwork, but I fear that she's going to try and clean everything up by the time court comes around and make herself look like a "poor single mom." We are requesting a guardian ad litem and an in chambers interview with my oldest son (who is about to turn 11) and I would think that any judge that really cared about the cirstances the children are enduring would have the heart and common sense to see that the children are in both physical and emotional danger living with this self absorbed person. If anyone has anything to offer as far as what I can due to ensure a better judgement this time around, please let me know! I can't bear the thought of my son suffering anymore!!!