Sorry I haven't had a chance to find links I promised you last night. Hopefully, others can help. I'm in a brain fog today.
People here use an expression to describe how you're feeling. The expression is 'riba rage'. (The rage is caused by interferon, but 'riba rage' has a catchy sound.)
You and your wife should both talk to your treating doctor about this. It is almost a universal problem for patients on treatment.
There are threads in Medhelp's archives about riba rage, some serious, some funny. You can put in a search for key words like riba rage, divorce, etc. One of many is at:
http://www.medhelp.org/posts/show/592545?camp=36
I don't agree with you that it's all your fault. Yes, you're irritable on treatment but you're doing this for the entire family's sake. Each of you has responsibility to make this work.
I think your wife needs to look for more creative and positive solutions rather than hit the road. She's having a hard time, too, and you both need to de-escalate. Go to a movie and get her some flowers. And talk to the treating doctor, together.