Dear Allen,
Brothers and sisters sometimes say stuff that can really hurt our feelings. I can definitely understand how difficult it must be to go to school and other places without your mom. I wonder if it might be helpful for your mom to give you a small object you can keep with you that reminds you of her. I remember when my mom dropped me off at school, I'd carry around a picture of the two of us. Anytime I got scared, I'd look at the picture and remember she wasn't too far away.