I was devastated at the sudden death of my mother when I was 14, I lost interest in many things, I asked a lot of qustions and didnt receive any satisfactory answers, the comfort I had felt from Jesus was not there anymore. This is obviously a very condensed version of events, the outcome of my rejection of God took about 6 years.
I wish I had an answer for you.
People like to butter it up and say: It was her time, blah blah, God needs her, blah blah.
Everything is for God's glory. Most of the time we don't understand how.
I truely hope that you recieve the answers to your questions one day.
This may be a little late, but I am sorry for the death of your mother.
Not that would make you feel any better, but I know how you feel a little bit. Although my mother is alive, she hasn't been there for me since I was 12. She's there but in her own selfish way. I ask God why also. I think I know the answer. At least I got a cool father.
Peace..