Hi My Yorkie Dog Has Congested Heart Failure And Murmur

hi my yorkie dog has congested heart failure and murmur almost 11yrs old he`s on 2 different heart med and fluid med and still cough and has had a bad episode Moday night could not breath and our vet doesn`t always call when we need her ,my ? is if he has pain and what can I do to help him ,also he has an enlarge heart at no:3 we worry so much and how will we know it`s time to give him peace ,still love to go out but can`t take stress ,always hungry ,please help me understand ?