im in a sexless marriage (and i dont want to be)

the title speaks for itself. im at my wits end. ive done everything i can think of to try to get him to want to be intimate and nothing ever works. ill come right out and say that i want to have sex, and its always one reason or another, or he says later and later never comes. i get tired of being turned down and ive just stopped trying to initiate, but he never does. he does have some health issues as of the past year which i am more than understanding of, but i know hes watching porn most days while im at work. if he has the drive for that, then why cant he have the same drive for his wife? its always some reason, or if im trying to initiate, he goes and makes himself something to eat. its like a fucked up sims game. any suggestions? im about ready to start sleeping on the couch at this point.