@hurtandlost,
I agree with DrewDad.
It is normal for your husband to have deep emotions when someone he has known dies, especially when this is a person he once had an intimate relationship with. He has every right to grieve.
So yes. It is right for your husband to be upset about the death of his ex-wife and especially right for him to be concerned about the kids he has helped to raise.
I think your feelings are normal as well. I don't consider you a bad person for having them. But, you do need to take responsibility for your feelings (they aren't your husbands fault).
But you have know more right to control how your husband feels then he has to control how you feel.
Feelings are feelings. Acknowledge them. Then focus on how you value the relationship.