@sally27 ,
So you've never been loved, rather the one to love but in that, coldly, that being, a robot doing what is required to get the job done right, that being, making people happy.
For what ever reason "someone" has shifted that to "you feeling happy" very happy around that person.
How long that will last for, I don't know.
The fact that finally you have stopped feeling worthless a nothing, not attractive enough and that may be the actual key as obviously this guy is more than attracted to you but you feel "this time" based on the past, that it's different, it's nothing to do with sex, someone finding you, the whole of you attractive to the core that it hurts in a nice way, is one of lifes lessons about oneself.
You do realise that this may be all that it is. You have found you and that this guy eventually will go onto someone else and profess the same, we can't live in a fairy tale dream because "anything" can happen. Then all those years with your husband are wasted, gone, because he will be gone.
Having said that, that may be a good thing.
"You married him with your head not your heart". So he needs someone to give him their heart.
Don't be selfish over " now is not the right time", why because it's Christmas? There is never a right time, only now, you don't put off today what you could do tomorrow.
If you feel your "heart" with this guy then at least you finally feel it so go with it no matter what the ending is but don't drag your husband down any further than you have, that being, you married him with your head not your heart, he deserves someone's heart and time to heal first to get it, don't use a fishing line and string him in and send him out and repeat any longer.