I'm a werewolf, and I'm grateful I'm alive. But there are also times I wish I wasn't. Eddie's condition is because of a chain of events that I set off. I attacked someone, that person created an army, and someone in that army bit Eddie. If I had the choice to go back in time and die before this ever happened, I might just make that choice.
And I'm sure he is grateful to be alive. And life does continue on, even managing this condition. But that doesn't mean he's ready to hear that, and it certainly doesn't mean he's ready to be told that his feelings of shock and fear and despair aren't valid, or that he's being ungrateful.