help about benefits

You wont qualify for DLA or what ever it is about to be replaced with, just by being inflicted with diabetes, no matter what type it is.
However, if you are inflicted with serious complications that restrict your ability to work, then you might be eligible for some form of financial support if you do not have any other income.
The only way to find out is to get a claim form, read its guide notes and then apply if you appear to fulfill the criteria for an allowance.

You can call the helpline for advice, number here: http://www.direct.gov.uk/en/Dl1/Directories/DG_10011169

As Hobs has pointed out quite rightly, DLA is for those who live with a disability not for those who have a medical condition without any complications.

ESA (employment support allowance) can be claimed by those who are unable to work through illness or disability but I'm fairly sure it would be affected by the fact that your wife is working and the income that she brings in.

If you have previously worked then you may qualify for the contributory based ESA which would not be affected by your wife's earnings. If your wife's earnings are low you may be entitled to Working Tax Credits. All benefit info is available at directgov website and there are also calculators for some of the benefits to work out if you qualify or not. DLA is only payable to those who need help with mobility or care.