Hi Amena and welcome to the forum. So sorry to hear about your poor health.
I think your IVA company are right about bankruptcy proceedings. There is no point in continuing to pay contributions you cannot afford, and the money you do have available is better spent on looking after yourself.
As you are on benefits, you ought to be able to petition for just £185 - so I would download the application forms from the Insolvency Service' website and read through them carefully. Soon you will be able to put all this behind you.
Regards, Melanie Giles, Insolvency Practitioner for over 20 years.
For further details contact me at
http://www.melaniegiles.com and view my IVA blog at:
http://melaniegiles.blogs.iva.co.uk