Self worth issues/ Shadow work advice

Hi everyone, thanks for reading this.

I'm struggling to understand why I consistently make poor life choices, not just in relationships, but career, living space, all of it. I feel like I missed something fundamental in life. I feel like all of my worth depends on what I can do for or offer someone. I know it's not healthy or normal and I don't know how to fix it. I have recently been the third party in some affairs with married men. I feel so badly and sick with remorse about it. I never wanted to be a homewrecker. Yes, I was lied to, but I feel like I should have seen it. I am missing too many red flags in life.

Does anyone have any advice on how to do shadow work or learn to find worth in something other than being a utility? I have tried to get into therapy but it's so expensive and it seems like no one is available. No one ever calls me back.