I Am Sick And Tired Of Broken Promises

It feels like it’s every damn day. She would promise she will help me with things or do something with me. And I can trust her because she’s my mother. Yet when the time comes for her to fulfil said promises it’s suddenly “ oh your little brothers needed help with this or sorry it slipped my mind we will do it next time I promise.”
I know she won’t keep any promises yet I’m so stupid that I believe She might keep this one.
It feels like every promise she has made in the last 7 years has been nothing more than lies to make me shut up for a little while. It’s frustrating that I can’t trust my own mother with anything.