I am afraid that stopping the IVA could cause more harm than good. Creditors will be able to add back lost interest and charges and will have no restrictions of enforcing collection, using the usual procedures. Nor are they compelled to co-operate in any repayment plan you might propose going forward.
The payments made are those which have been agreed by the creditors.
Depending on how long you have been in the IVAs and payments already made compared to your original debt, and your husband's condition, it might be possible to propose that the IVA be concluded successfully, based on payments made to date, rather than failed.
We cannot really add much more to the replies already given on this subject in your other posts. It boils down to you and your IP working, hopefully, together to find a way through this. Have you discussed the situation with him or her yet ?
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014 http://foggy.blogs.iva.co.uk