You can ask for a repayment break while you seek new work. Ultimately, you will need to do a fresh I&E to ascertain what you can then afford. If you cannot make the IVA repayments at all the arrangement will fail.
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014