In 4 Days Out, 9th episode of the 2nd season of Breaking Bad, Walt and his family are told by his doctor that his cancer is in remission, which is obviously a very happy moment for his family. Walt is initially shown to be happy - and rather in a relieved disbelief of this fact - but when he looks at his reflection in the towel dispenser just minutes later, a frustration suddenly builds inside of him, causing him to punch the dispenser? What is the reason for this frustration? Is it:
A. He realizes that all the bad things he's done are for naught, and since he isn't dying he can't justify them to himself
B. He has entered a life that can only be escaped through death, i.e. if he lives on, he'll have no option but to continue living a "bad" life
Or is it both (or something else)? Further, what impact does this have on Walt's future decisions, e.g. him deciding to cook for Gus even though he no longer needed to?