How about I decide to refuse to support my wife through her diagnosis after her cheating?
Did you talk about her behavior?
She cheated on me because she said I forgive her too easy.
I can understand you being upset. It sounds like you guys never resolved her affair. It's not good that you're planning to withhold support when she's sick.
E: She blamed me for her affair and told me I was depriving her from sex.
I'm sorry this is happening. If your spouse is in a bad way, you should try and support them regardless. It is best to try and work through conflicts so they don't continue to hurt your relationship.