This has led to some really interesting replies.
Something I have learned since the breakup is that: I wasn't turned on by my ex, because deep down I knew he wasn't right for me, deep down I wanted out. We've had some dark times and I just could not find peace around him, even though I desperately wanted to. So much of our relationship was great that I wanted to force it to work. The sex problem was just the most un-ignorable repercussion of the deeper trouble. Posting my dilemma on here was a way to help me process everything.
Losing sexual interest has
happened to me once before, but it was with a guy that I wasn't really physically attracted to in the first place.
I know that waiting until marriage for sex is not a popular choice. Often people presume that I am naive, prudish or blindly devout for choosing to. But it's something I have considered very deeply. And I don't judge other people for living differently.
When I look inside and think about my life and the world, what makes my heart come alight? My real, soaring joy comes when the things of this world drop away. When I think about love and the beauty of the universe and God. It is only when I think about God, when I am with him, that I feel fully alive, and fully at peace. When my heart is aglow like that my own life seems so short and I want my all choices to be for good.
The excitement I feel from getting it on with someone (yes I'm not a complete rookie) is fun and intoxicating, but it's also about wanting to bond deeply with a person, and give them myself. If I'm not sure I am going to remain with that person, for me, it comes with an interior conflict - the bonding could be in vain and just cause a ton of heartache later. It is easy to gloss over this and make excuses like 'it's not hurting anyone', 'It's an expression of love', 'Everyone else does it and loves it' or even 'I need to sleep with him so I don't loose my sex drive'... but for me, the deep sense that it will bring something good is always missing. My motivation can always be deconstructed, it's shallow and not from that place of joy of God/love/goodness.
I have to follow my heart. If I don't, to me, that's a much bigger waste of these years than not having sex