Dear Lisa
You need to stop beating yourself up on this. You did the best you could given the circumstances and the lack of information. Did not your wife ask you to hide these things from her so she is implicit in keeping the cding a secretive pursuit. She also betrayed you by acting the way she did placing all the blame on you which you appear to have internalized. You cannot control how she deals with the ingrained prejudices she grow up with. Some people can overcome them, others cannot. The outcome would have been the same regardless of how truthful you thought you could be.
Or put it another way. If you had exposed every nook and cranny of your mind to her most likely you would have been divorced a long time ago and would not have had this long relationship or a beautiful daughter. Would that have been a better outcome? Were there not many happy and fulfilling moments for both of you that you would never want to dispense with?
If the two of you have indeed grown so far apart that the effort of forgiveness which is at the heart of every loving relationship is too much for her to give anymore, then it is time to move onto another place. Start looking forward and do not dwell on the past, you can still have a strong friendship and raise your daughter into adulthood together. You may even find that when the weight of marriage is gone the two of you may connect better than before.