SURPRISE!! Child Support Modifacation AND You are in Arrears! GRRRR

My husband has 2 boys ages 15 and 18 from a previous marriage and child support he has been paying faithfully and on time. We have 2 boys together. And I am out of work. Needless to say we are stretched so tight! Well, we just got a modification of support letter from Montgomery County PA. It naturally says that the 18 year old has now been emancipated since 6/12/13. Great right? But wait there's more.. The 15 year old's support has MORE THAN DOUBLED !! Since that date It went from $727.62 per month for both boys to $836.26 for only 1 boy! AND they now want Steven TO PAY INSURANCE as well. AND they are placing him in arrears for $404.43. OUR boys don't have insurance because we cannot afford it!!!! They have gone without all these years so their two older brothers have everything they want!!! His Ex has had her boys on her work insurance all this time. AND she has NO mortgage or rent AT ALL!!! What do we do. NO MONEY!!! = JAIL and I end up homeless with my boy while she lives it up!!!

We live in Florida. And the ex-wife lives in PA. We received the modification letter yesterday. With no warning. It says plaintiff ExWife's name and defendant Hubby's Name. So we can only assume it was filed by her. It is title Order of Court - UNALLOCATED and the a check mark next to modified. It reads.

And Now 24th day of July, 2013 based upon the Court's determination that th