Gosh how did I miss this thread. This is something we have been struggling with. I have an autoimmune diseasethat untreated I am unable to function. I am bedridden and unable to move. It is a struggle to use the bathroom let alone take care of my kids. There are several drugs out there to treat my PsA. All have failed except the high danger drugs for pregnancy. The ones I am on now it has a 100% chance that is 1-0-0 that the baby will die. Most died in the womb none have lived more then an hour after being born if they make it that far. It has a high mother mortality rate also something like 45%. The other drug I has this incredible high birth defect rate also. Where does that leave me? If I do not take the drugs, I cannot parent my own children. If I do take the drug and get pregnant I have signed the death warrant for my child.
If this were me, I would have no qualms whatsoever about enacting some permanent method of BC. This is an extreme situation, and your family needs you to be there for them. Your marriage needs the God-given gift of unity in a sexual relationship, so IMO permanent abstinence is not the answer either.
I'm sorry that you are faced with such a tough decision. I pray that Our Father will bless you with the wisdom of His Spirit to guide and comfort you.