Hi there Pearson37 and welcome to the forum
As far as living expenses in a DMP, it is in everones benefit to record the actual costs per month or in the long run your DMP will fail as you cannot afford the monthly payments. Your creditors may not agree and continue to charge interest but you can still continue to pay what you can afford.
having said this if you have children that are adults living at home they should be contributing and this should be taken into consideration in your budget as you need to be seen to be paying as much as possible to your creditors for them to stop interest.
I have attached a link to the Beat my debt living expenses guide which is very useful.
https://www.beatmydebt.com/debt-managem ... nses-guide
If you give a little more detail about your situation we will may be able to suggest further help.
Please keep us informed.
Melissa McDonald writes articles and blogs about debt solutions and how they can be implemented. She aims to reassure people having debt problems that they can be debt free!