I'm going to block my mom's number because she called me for help.
Is your mom okay? Frankly, that is a very unkind thing for you to do.
No, she is just bothering me. I'm not listening to that bullshit
If you aren't able to help your mother, then just let her know that you can't help her instead of blocking her number. If you block your mom's number for a trivial reason, then you're likely to damage your relationship with her.
I'm going to do it anyways and think that I'm mature enough to make my own decisions.
Ignoring your mom, especially if she might really need help, is not a good thing to do. I understand that parents can be annoying at times, but you should still respect them and have concern about their well-being. You should call your mom back and make sure she's okay.