first the good news. you've risen to the challenge of going dark and have been able to maintain this very difficult position. i congratulate you because this is so hard to do.
don't assume, however, you know your husband's state of mind regarding this. for all you know, he could feel very hurt and alone. you just don't know.
because you have been dark for a substantial period of time, you might consider sending up a trial balloon and then paying close attention to how he responds. a cold shoulder will obviously tell you to back off and wait longer. lukewarm invites another small step forward. go carefully.
my instinct tells me that you need to let him know you have softened on the dealbreaking issue of your stepdaughter (i also know these are tricky and difficult issues, but i assume you now have a different perspective on what you value most).
consider something as simple as just validating the very difficult position this puts him in by saying something to this effect: "i'm sure it's been very hard trying to be both a good and loyal father and loving and supportive spouse at the same time. i wish i could learn to be more helpful".
also think about leaving this message through an unexpected medium. if you are usually text messaging, how about a hand-written note - which hopefully conveys respect and consideration.
there's a very good chance your husband has a lot of mixed feelings, including some positive ones. on the other hand, if he doesn't see light at the end of the tunnel on the deal-breaker issue, he may not think it's worth moving closer.
good luck and kudos again on how you've done so far.
