It's okay, hon, I've talked about everything! It is whatever that is affecting one's life that is important. Your mother was very important to you and I'm sorry that your W does not have the maturity or unselfishness to have overcome before your mother passed away.
You probably would not make much progress in telling her about your mother passing away, IDK. But, I think by contacting your W that it would cause the kind of distraction you don't need at this time.
As far as how you have responded to the death of your mother, don't be hard on yourself about what you do or do not feel right now. As you said, we all react differently. Sometimes we don't react like we thought we would when we knew we'd be facing it. It hits us in stages, so just allow whatever you feel (or don't) to take its course. Your mother knew you loved her and that's what counts.
I hope that you will be able to talk to us or put your thoughts about your W aside....or whatever you need to do in order to get though the next several days. It's tough, no doubt about that.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!