John -
My ex husband was born with spina bifida and hydrocephalus, i was married to him for over 10 years, and i was his caregiver for over 6 yrs.
One thing anyone thinks and feels when they are sick or have limitations of any kind, is that their suffering is their own and no one else feels pain.
They get wrapped up in their problems.
Your fiance may feel the same way, and the minute she hears she isn't doing something to your liking, she will shut down.
What anyone healthy or ill need to understand is that intimacy is a word for a wide range of things.
There is sex, "being intimate", fore play, cuddling, affection, passion, ect.
Being intimate or wanting intimacy can be simple as a hug or kiss, cuddle, holding of hands, spooning, ect.
Everyone needs to try and explain to their loved one what they miss or what they define in their mind as affection and intimacy.
The smallest touch can do wonders.
I do know first hand about being shut out and having no affection or intimacy from a person who is sick or disabled, and it is the worst feeling in the world.
Communication is key, but many times that is impossible with someone who just sees their own pain and disability.
Your feelings are valid, and don't be ashamed for wanting some closeness or touch.
Instead of using intimacy, say i need some affection or touch time.
Try to research free counseling, ect.
If you need a support group for being a caregiver to your fiance, i can guide you to a great site, just message me.
Take Care and Stay Strong to all.