No, the answer is likely going to be dictated by math and your respective incomes. The statute provides for guideline support at 20% of net income for one child, and 28% of net income for two children. So your ex would be paying you support at 20% of her net and you would be paying to her 28% of your net. However the math works out will likely be the answer to your question, although deviations from guidelines are possible depending on your particular situation.
File a motion immediately to correct the error, point out the Judge's correct ruling and include the order as an exhibit. Ideally, the Judge has notes that she/he keeps which will support your request to modify the order and it should not be much of a problem. .
You should talk to a lawyer right away. This type of harassing and alienating behavior could be grounds to file a petition to modify his contact with your children, including reducing or supervising his visitation. The court could also order an alcohol evaluation and mental examination, which could prove helpful for your case as well. In any event, you need to move quickly. The amount of time in between when the abuse/harassment occurred and when the court is first made aware of the behavior is...
How long ago was your divorce judgment entered? Were you represented by counsel at the time of your divorce. There are very strict time limits on when you can move to vacate a divorce judgment or, if appropriate, sue your attorney for coercing you into signing a settlement agreement that was not in your best interest. You need to speak with an attorney immediately to make sure you don't miss one of these deadlines.
It is a shame to see the disparity between men and women in family law courthouses throughout the state. There are far too many men that want nothing to do with their children, or just simply want to treat their children like a liability and effort to spend as little money as possible. It appears as if you're in the other camp, and if so I commend you for it. Far too often fathers are shut out for no fault of their own.
Also your failure to pay, although it seems as if it wasn't done in bad faith, could be grounds for a petition for contempt to be brought against you. The possible results of this could be monetary penalties and/or jail time depending on how egregious the judge believes your conduct to be, but even if the judge denies the contempt petition you're still forced to deal with various court appearances, a contentious proceeding and likely attorney's fees. It's best to short circuit the possibility...
To clarify, if by "arrearage" you mean overdue support, then it starts when you miss a payment. If you mean by "arrearage" when the court may determine your financial responsibility for payment of support begins, then the answer is it may be determined to be at the time of the filing of the petition, or some time before or after.
While I agree that since you're represented by counsel we can't give advice, I consider this your question to be more procedural than anything else. Quick answer to your question is no. Long answer is that motions like these are filed very regularly and they don't and can't factor into a judge's decision. Frankly, unless there have been multiple motions for default and failures to appear, the judge has probably already forgotten about it.
I agree with Mr. Gotzh, but I'd also add that if you're also supplying OTC medication you should be keeping receipts and a log for all expenses to later use as a set-off if your ex persists in her demands for your contribution. In poker terms, see her bottle of Nyquil and raise her a box of gauze.