Hello and thank you for the opportunity to assist you. My name is ***** ***** I will do my very best to answer your legal questions.
If you have already tried to get the amount reduced, but couldn't, then I'm sorry to say that it seems unlikely that the judge will change his mind. Perhaps the judge thought that you are purposely underemployed (i.e., making less than you should be making). If that's what the judge thought, then he can award child support based upon what he thinks you should be making rather than based on what are actually are making. Nonetheless, you can certainly file a petition to modify the child support and argue that you simply cannot earn more and that you are sinking more and more into debt. If you are more convincing, or if you have a different judge than before, then it's possible that the order will be modified.
As for the arrears, there is nothing that you can do about that. Regardless of the fact that you hadn't been working, your children still needed to be supported, and so the other parent had to take on the support of two parents. The arrears is a legitimate debt owed to the other parent.
I am truly sorry that my answer is bad news for you, but please understand that it would be unfair to you (and unprofessional of me) to provide you with anything less than an honest response. However, if your concerns were not satisfactorily addressed, then please let me know, and I will be happy to clarify my answer.