CSA are saying I have arrears dating back to 1994!

The Csa put a deo on myself in November 2014. i wasn’t even contacted otherwise I could of sorted something out.

They say I have arrears dating back to 1994 of £13000. Now, my kids are 30 and 25 but I’m still paying for them!!!

My monthly wage works out now at £4.72per hour as I’m paying £463. / month out. I work 192 hours a month and my take home pay is £846..

Surely this is illegal and it’s put me at the point of just giving up and crawling into a box.. I AM DESPARATE SOMEONE PLEASE HELP.