Esa Questionaire after 5 years ! help

Hello there, im new here . 
I have today received an esa questionaire , but i have been on esa for around 5 years within the support group for a Severe heart condition i have which affects my abilitys to breath properly amd get around my mobility is severely restricted , i read on the form ive to fill it in & send it back for them too decide if im still entitled to esa , but on a few other sites it breaks down the points and if your walking ability is affected and you cant manage to walk upto 50 metres then thats a descriptor for being in the support group basically nothing has changed and just wanted to know the ins & outs . 
any help would be much appreciated 

Cheers .