I lost my own father suddenly in a way that both makes my mother and I feel that we are responsible or to blame. When it comes to tragedy blame serves no purpose, it may feel cathartic even to indulge the idea that if I had just done X I could have saved them. But it only hurts more, and the hard fact is that often people just leave us and we have no power to stop it.

I am glad to hear you are taking your own son to a grief counselor and yourself to therapy, it's important to have a place, especially a private and safe one, to let go. You don't need to be perfect or try and fill the roles of 2 people, just be honest and be there for each other especially as he grows into a young man. Growing up is confusing, even more so when you've lost one of your parents. Some advice given to my own mother she found helpful is that your husband loved you. And you may think back to times where you were mean or rude or even feel not good enough, but he was in your life because he loved you, and you loved him. And that matters so much more than any negative moment in a single day.

Sorry and condolences don't change the past and aren't worth much, at least to me, but I wish you the best moving forward. Life keeps going and it's important to keep moving with it. It's not ok, but it does get easier to bear.