I lost my job so ex has gone to CSA and having new man adopt my kids

I split from my wife two and a half years ago but we stayed married for the sake of our girls until she met her very wealthy new partner, whose wife had died. I was paying her directly every month, for much of the time more than what the minimum CSA suggested (at the time I was on £40k).

I lost my job in February, but still made the March payment. I explained to her that when I was back in work I would resume the payments, but she has gone to the CSA and they are now taking 40% of the minimum wage I am earning in temporary roles.

She has claimed to have an income of £139 a month from benefits, but is actually a company director living in a massive house, whilst I am living back with my parents.

She has got the council working on him legally adopting my girls and I really don’t know where I stand with anything at all right now.

Any help would be greatly appreciated.