help with nortern rock and cca

I currently have zero equity in my home as I purchased a £200,000 house two years ago on a interest only mortgage. In the last two years simlar houses in the street have sold for around £215,000 to £220,000 and because of this I didnt regret my decision to 'move up the ladder'. But I have no doubt that in the current climate the price I paid would be at the top end of a mortgage valuation. To add to this I have also used circa £15,000 of the loan facility from NR.

I have now received a letter to say that my mortgage and loan payments will increace by a considerable sum despite the current low rates of interest.

I had first thought this thi would be affordable but now I am not so sure and my mortgage rate appears to be 7% above a base rate that will not stay at such a low rate for more than a short period of time and I am concerend that within 24 months I will be looking at rates of circa 14% with a monthly payment I cannot afford.

I have been advised by a mortgage broker that I can get another mortgage but the loan with NR will be a problem as the interest will rocket and could decrease my chances of being accepted for the mortgage.

I am told that 90% of such loans are not legal and are being made void due to the legal agreements being out side of the law. All of this sounds very dodgy but as someone desperate to keep hold of my house it does sound worthy of investigation.

Should I get in touch with the company he recomeneded or should I send a letter to NR myself?

As my agreements were signed in March 07 but I moved in June is it even something I should look at?

Thanks all for any help in advance.