My mom doesn't want me to wear hijab?

You should first try to improve your relationship with your Mother so that you can speak your mind without inhibitions. I never understand people who are too shy to have a straight talk with their own mother. You should be like friends to one another. You should be chums... Go to her and explain how you feel and that you think you would feel far more comfortable wearing the Hijab and that you are ready for it. Just don't be pushy but explain kindly and with reasons. Also, pray to Allah for your Mom to have a change of heart. Prayer in these circumstances especially always seem to work.