How do I modify child support in Chicago if I’m working less?

My son’s mother and I both live in the Chicago area and I’ve been regularly paying child support for over 5 years. My work has cut back my hours during the pandemic and have not let us know when, or if, we’ll be returning to our regular hours. I’ve tried to make the court-ordered payments as long as I can by working side jobs and selling some of my property, but I can’t keep it up much longer. My ex says if I don’t pay the exact amount in the court order she’ll file for contempt against me. What can I do to get my child support lowered, at least while COVID-19 is still causing shutdowns, and what do I do if she does file contempt papers?