OK Bob - this is how I see your case - but do bear in mind that I am just one of the experts on the forum and others may have differing opinions. Also, you much consult with your own IP as he/she has detailed knowledge of your case, which I do not have to hand.
You are halfway through a five year IVA, and struggling to make your payments but expecting a pay-rise shortly. Why not ask your IP if you could reduce your payments temporarily for the next three months to say £300 until you get back on your feet. (Good luck with the exams by the way!)
With regard to the property, you have pledged to raise your share of the equity, which at the moment I would calculate at approximately £20,000 after allowance for notional costs of sale. I do not think that you will have any problem raising that sort of money on a re-mortgage, when the time is right. Many clients of mine have done this very successfully, regardless of their ages, and once the IVA has completed you will have than £500 extra to meet the increased mortgage costs.
Being three years in to an IVA, I would certainly not advise you to go bankrupt at this stage, as your equity would be lost to the bankruptcy and you would probably still have to make contribututions for the next three years.
Although your case has a nasty history, I do not feel that your IVA - or you personally - are in any sort of jeopardy at the moment. I am glad that you are finding the forum useful, and please continue to post if you need any further assistance. We can also recommend a good mortgage broker to you as well.
It would also be really helpful if you could reproduce exactly the wording with regard to the property equity on the forum for more definitive advice.
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