lol!
One thing you NEVER want to do is blame someone else for what you haven't accomplished. It's not your moms fault, she isn't holding you back. Someone who is truthfully committed CAN'T be held back! Consider that you might not be pushing as hard for it as you should be because where theres a will, theres a way. You gotta do what you gotta do man. No excuses, no exceptions.
What should you do? Keep writing raps, with or without your moms support, and be prepared when the opportunity to record comes.