With a mortgage shortfall of £50k, and other debts of approximately £7k, it will take you approximately 8 years to pay off the debts, assuming that creditors will not charge you any ongoing interest, which cannot be guaranteed.
An IVA ought to last for 5 years only, but you will need to get the support of the major creditor, and as you are going to be required to raise equity during the final year you may find that you end up paying creditors in full - depending upon the value of your property in the final year and your ability to raise additional funding.
I suggest that you now take advise directly from an insolvency practitioner, who will be able to explain all of the options you currently have available and discuss an appropriate way forward.
Regards, Melanie Giles, Insolvency Practitioner