i'm not sure how this issue could have persisted for a year - i would take advantage of her patience and work with her in trying to see if this relationship can be salvaged regardless of the outcome of your health. Some people will place sex above other aspects in a relationship - but there will always be those who don't. No one will be able to replace your current girlfriend but i suppose the other side to that argument is that you can't say you won't be happier with someone else. It's not a win win situation but as Spock says; there are always alternatives Good luck.