You are not alone. There are many couples who stay together for financial reasons and there is no intimacy in the relationship. We all must give up something in a relationship and you will feel less self loathing if you are true to your feelings of not wanting to have sex or be intimate. It is more like a brother sister arrangement.
You just must remain true to your feelings and not violate yourself.
You have to decide if when you were single things were more sexually satisfying and I would wager to say they were about the same. At least you have a place to live and some posessions.