Hedwig - sorry in advance for long post and probably an unpopular opinion.
This is a topic I can give perspective to as the recipient of support from my STBXWH and a 2x breast cancer survivor (Catwoman, not sure I knew that we had that in common, will have to pm another time about that
My Dday#1 was just before the 1st diagnosis.
I was in the midst of raising two young boys one a difficult child with autism and had just JFO about PA#1. WH stopped the A and turned his attention to me and the kids (as much as a narcissist is able, anyway - he didn't want to look bad in front of others, too) but I do believe he was compassionate and supportive because he wanted to be. I am/was grateful for that because for me, while I was strong every day for the kids and went through all the surgery, chemo, radiation and complications with my head held high - he was the one person I allowed myself to cry with at night when I did feel angry and scared that it was happening to me. And he was there to comfort me, many, many times. My experience was different than Catwoman's. I really needed him then and I cannot imagine how I would have done it without his support.
Unfortunately it turned into false R later, but I didn't know it. I just noticed that after being Mr. wonderful during the first cancer experience then suddenly when I was strong again he became mean and distant (he began A #2 a year after I finished treatments).
Then I was diagnosed again. same cancer, same breast. This time I had double mastectomy. I didn't know it at the time, but WH was in the midst of his EA/PA with OW that he had strong feelings for. He temporarily stopped it (she had an ounce of decency to agree with him on that as her FH died of cancer) and WH again turned his attention toward me and the kids.
While I was better equipped emotionally to handle the cancer having been there before - I was still grateful for WH's emotional support because I was so angry and sad that how could it possibly happen again so quickly after I had gone through so much treatment - and he totally understood that. In hindsight the second time he was definitely less emotionally involved in the support (somehow a little less loving in a husband way.?) . But it didn't bother me, he was still supportive. And again, as soon as I had fully recovered from the surgery - he was back to being mean and distant and critical - clearly had resumed the A and was faking false R in counseling because he felt guilty about wanting to possibly leave the marriage after me having cancer twice.
I can tell you that a few months after the surgery if he would have come to me and just told me he wanted to end the marriage I think I would have been okay. He told me later that he just felt like he didn't want me to suffer anymore (he was doing me a favor
) but what he didn't get was how much more I was suffering in anxiety, depression, confusion due to his verbal abuse and gaslighting - but now I know he subconsciously always wanted to be with AP when he was home "doing the right thing" really?
This went on for 2 more years until I recently had my 1st phase of reconstruction in January this year - which again I've have complications. Again, he was good to me during and a little after the surgery. But this time, he was even able to be annoyed with me already even just 3 weeks after the surgery. And the reason for that, is because AP ended the PA just before my surgery. So now he's just pissed and grieving about how he stuck with me through everything and now his AP had had enough of his "compassion" for me... And that's when I had Dday#2.
I'm only three months out of reconstruction surgery #1 and have #2 upcoming in September.
Things are different now because STBXWH is out of the house and I am moving toward D. But we've had a conversation -and have agreed he will be there for me and the boys to support us during and after my (hopefully last) surgery. It will be platonic, but I STILL am grateful that he will be there for me. It feels natural and I know I would be disappointed if he chose not to be. Not because I'm pining for him - NOT AT ALL. But he knows me, my journey, and the father of my kids and dad "should" be there to help. And if he's banging AP while he's supporting me, I could give a shit. He can move on right away once I am safe. He doesn't need to even stay at the house. But he was my partner and friend for 25 years and it will be a comfort to know I can count on him for this.
I'm sorry this is so long and a lot about me - but my feeling for you is - as long as you are not going into support WH because you are hoping it will get his head out of his ass and he will have an epiphany that after all you are the "one" and it isn't the "pick me" dance - if you know you are able to set that emotional boundary - I absolutely think it is natural and appropriate for you to be there to be supportive. If you are a caring compassionate person by nature - why on earth wouldn't you do what you could to support ANYONE going through that kind of experience? I mean, this isn't like going back to an addict and supporting their addiction with codependent behavior.
Cancer is scary and is a different experience for every one - and degrees of seriousness and fear/anxiety/strength are completely subjective to each person. Supporting your WH is not being codependent or weak, IMHO. It's being a human being. Just don't get sucked into some kind of hopeful vortex for the epiphany.