Hello exhausted, just to offer another viewpoint, I am in a DBT program right now for my depression and I am finding it to be very effective. And yes "Radical Acceptance" is a DBT based skill.

However I don't think you need to accept your depression, instead there are other DBT skills to help you manage it. "Radical Acceptance" is a sort of technique for when other management skills aren't working, I think it was appropriate for the case with your daughter to help you in accepting her situation but for yourself there are other skills in DBT that might help, especially since "Radical Acceptance" was effective for you.

If you are interested see if you can find some DBT based therapists or a group DBT program or do some research on DBT Mindfulness and Emotion Regularion... These are two of the four areas that DBT focuses on. The Mindfulness helped me a lot almost immediately and I've been growing into the other skills with some practice.

CBT might also be an effective option for you as justafriend said.