Well at the risk of incurring your wrath, do you actually KNOW he hasn't got cancer? Just because he hasn't shown you proof doesn't mean that it's not true- I actually know a lady who was diagnosed with cancer and the first thing she did was go home and walk out on her husband- sometimes it takes people that way- and his being angry and bitter could indeed be related to that. Now if he hasn't got cancer that's a different matter- he clearly wants some space or to cool things down with you and in the absence of him talking to you, you'll just have to accept that he wants to cool things down. Don't dwell on it, you can nurse a grudge forever but it'll never get better, and you'll be the one left feeling hurt and angry, not him.