I am sorry to hear you lost your mother. I know what a sadness that loss brings. My mother died 10 years ago this month. I had been with her the whole day and when I left to rest at home for a while, she died. I felt so guilty for a while for leaving but I don't dwell on it now. I, like you, wondered if I was patient enough, loving enough, etc. It is common for people to do that. Now I just miss my mother from time to time but I don't beat myself up anymore about how I handled her illness and death.
Hugs to you. I hope you have some support people at this time to hold you up when you are feeling low.