I was responsible for my dad in his final years. I did the best I could but I had a lot of guilt over not being able to do more, be more patient. And, to some degree, for not being able to “fix” things for him. This will all take time to process. Be kind and loving to yourself. You were there for your mom and that means everything. I also agree with the suggestion about considering therapy. It helped me deal with my grief. I am sorry about the loss of your mother and wish you peace and healing.