couples ESA

I've recieved a letter from housing benefit that says we might be eligible for couples ESA and I'm not sure what to do. It seems that when anybody applies for a new benefit they are knocked off their original benefits until a new claim has been established, I'm really scared my daughter had her esa cut off and didn't have any money for 3 months and mummy here paid for everything out of my savings now I've no savings left. Should I try for a new couples claim or leave it as it is