I’d say first step to anything is to decide you want this.
Find something that changes your perspective.
If you can then fake it til you make it as in tell yourself you’re not worthless until it sticks.
it is all in your head that you’re worthless
The same goes for no confidence. it’s all in the head.
A start would be to just tell yourself you’re not even if you don’t believe it and then find other ways to build it up.
As in magick wise have you ever heard of Bathin? she shifts and changes the way you think and percieve things. She changes ones thought process to that of your desire so if you desire to remove toxic shame it is well in her power to shift your thoughts.
from the little research I did it seems connected to past things/ childhood even? Revision technique reprograms your mind and ”changes” the past to that of your desire. So in you’re situation the RT would be focused on the things you experienced that caused toxic shame and to remove those in your past.
I believe anything that works with the mind and emotions could help you in this situation. King Paimon, Orias, Dantalion.