wife is angry with me for wanting to be involved

Every single person with breast cancer is different. This is my opinion and only my opinion. Feel free to reject it out of hand.

She may believe that because, as much as we care and love someone and no matter how well we know a person, frankly, we really cannot understand 100% what that person is going through. We can try (and by all means we should try!), but we cannot Know.

Sometimes (often, I admit), when my friends have asked me questions that I need to know or made suggestions (no matter how well-intended) it infuriates me. I feel like it implies that I don't know what I'm doing or don't know how to take care of myself.  (I will get to that, people! I really will! Just give me some freaking room! I'm trying to wrap my brain around this whole cancer thing!) 

I have an aggressive cancer. It grew, and continues to grow, rather fast.  Yet, I can honestly say that rarely have I felt a need to rush. Because -- god's truth, frustrating as it is -- there will ALWAYS be another doctor's appointment or an another test result or another phone call or another opportunity (e.g., phone call) to ask the question. Which will spawn 14 other questions.

So I didn't resolve to ask all the questions. I resolved that I would never make a decision out of fear.  And it has served me well so far.

What can you do?  For me, it meant the world to me when my partner just picked up my hand and held it. Or maybe brought me a glass of wine, or sat down next to me and put his arm around me. (Or stroked my hair. I never knew how much I liked that.) Or just let me ramble. Or rant. Without offering solutions but just saying things like "I hear you." Or "That's tough, [term of endearment]." Or "How'd you feel about that?" And the occasional, "Do you wanna know what I think about that/what I think we might do?"

It's understandable that you want to make sure all the important questions get identified and answered.  And they will.  But for me, it was really important that this was "my" experience. I needed to feel confident and capable.  And I needed people around me to believe/know that too.  Just as I needed people to hold my hand, or let me cry or see me break without thinking that I was coming undone and maybe wasn't all that capable. The support of my friends and family is the reason that I am a fiercely strong person, and I dare say, sane.  So far.

I worded this in terms of me because I don't know Sue.  But I am rooting for both of you.  I really am.  It's hard.