Considering the amount of progress you've done, your mom should not have the legal right to take your child away. But you DO NEED a stable source of income before you go down the road of custody battles! There's also all kinds of help with food stamps, daycare... all for free so you can work or go to school. If your mom tries to fight you, you'll need a good lawyer! She's just being protective of your child. May be she thinks you may relapse. So prove her wrong that you can do it. The best way is to convince her you are doing fine and you are never going back to your old way of life! It's always nice to have your mom on your side. She just needs some convincing.
But you do need a j-o-b right away!
Good luck, hun!