Electric cooker (IP16)

Our cooker was second hand when we got it about 10 years ago, and is now covered in rust and only has two of the four hobs working, plus the oven and grill no longer work correctly...along with my posts asking for a fridge freezer and a sofa bed, this is the third most important thing we need...as my husband is disabled and I am his sole carer, we are on benefits so can't afford to pay for large items like this, so any help would be greatly appreciated in advance