My ex-wife owes me over $5000.00 in child support and only pays me once every 3 months. What can I do?

You never emtioned your state, had you I could of given you information regarding how your state enforces child support. The child support services can suspend the drivers licence against the non-custodial parent for non -support, alo tax refund checks can be taken, if he/she owes over $2,500.00 then he/she cannot get a passport, in some states failure to pay court-ordered child support carries crimmal consequences under both the state and federal statues. You can also contact the Bureau Of Child Support, The Child Support Help Line at 1(800) 932-0211 and press #4 M-F 8:00-4:30 PM
As for your ex violating the court ordered agreement by discussing the custody arrangement might be a little harder to do something about, you would need to file a motion for contemp against her, and in doing so you would need an attorney to file those charges, with proof showing the court that your ex has violated the court order.