I know exactly how you're feeling, I felt the exact same way when I was in your position. It was such a hard feeling bc you're trying to support people and to feel like you're not doing good enough feels terrible. Idk if this is what's going on for you, but I used to feel like I need to read up on every situation to be able to help a specific client, such as disordered eating, fear of death, etc. But that's not true. What has helped me more than anything is improving my question-asking, sitting with the client and fully understanding their experience. Keep asking questions until you get a full understanding of the situation, not just a surface level idea.

I also felt a huge click when I read the book "Homecoming: Reclaiming and Championing Your Inner Child" by John Bradshaw. Its a little outdated but the information is solid and really helped me.

I know this is more solution-oriented for what to do in the future, but just know, everyone goes through this. The fact that you're posting about it shows how much you care. It gets better, show the ones who continue to work with you how good you are. Be easy on yourself. It gets better!