Remember that this disease DOES muck with your brain as much as your body ..... has your dissatisfaction with the marriage increased in leaps & bounds since your diagnosis ... or has it just made you less prepared to sit it out, 'as is' and wait to see if it gets better? Have you both had counselling? Can your Cancer Centre put you onto a Breast Cancer Counsellor?
Do what is right for you, @Brownowl .... this cancer thing can really tear people apart - particularly if one partner is not caring & supportive of the other going thru the cancer .... and if teenage kids are involved, possibly even worse! :(
Are you able to get away & have a total break from the house & responsibilities for 2-3 weeks? That may 'wake them up' to just what you DO do around the house & their lives ..... it could be the wakeup call they need .... or do you think the marriage is beyond that already?
Sending big hugs, take care xxx