If your mother is doing drugs and other illegal things, and if i were your father, i wouldn't want you around her, either
Your mother needs to give proof she's not doing drugs and has changed (if she has). She would need to go through a rehab program, get drug tested or whatever a judge in a court of law tells her she needs to do in order to make it so she can see you again. So, if your mother is so hell bent on seeing you, she will go through the process to turn her life around or to prove she has done this (if she has). She'd probably need to discuss it with an attorney.
I'm sure all this is distressing to you, but if your mom left, was doing drugs and didn't want the responsibilities of being a mother, i'm sure it took a toll on your dad... and i'm sure he's bitter over it.
I'm not saying that you need to find someone else as a mother figure, but as far as the Mother's Day gift goes, you could have still made one and given it to a woman you admire.
I'm sorry you're going through all of this.