The timeline seems to make perfect sense here for the woman losing those initial “tingles” and simply not caring about your physical needs. Over 5 years in a relationship and 3+ of those years being a dead bedroom? She is broken. If she actually cared about you, she would find ways to work on herself and fix the problem. She became comfortable with what you offer and found out you wouldn’t leave her after the sex was cut off. She will never change, and is now under some hilarious delusion that you want to actually commit to her. Get rid of her and find someone who actually desires you.