Going back to your original point about wanting to cut household costs so you can quit work and start your own business, how realistic is this ? What sort of business are you planning? Will it need capital, premises, other start up costs, or just time? Do you have any savings?
Will one of you continue to bring in an income to cover the basics, is this the basis for the £2k?
The expenses you have listed above are a little above £2k, but there is a lot of scope to cut back, without having to go to extremes, especially if you can get a cheaper mortgage. However, you will probably need to remortgage before you go self employed, otherwise you might not qualify until you have at least 3 years of accounts showing a profitable business.
The main areas to look at will be mortgage, personal spending, car insurance and maybe a little off your internet costs. You probably won't be able to get much off your food bill, if this also includes the dog's food.
You could have a look at the Moneysavingexpert budget planner, and also get the weekly email for ongoing tips about living a more frugal lifestyle.
www.moneysavingexpert.com/banking/budget-planning/