Feelings about project cost

I have a project that has a cost over run. Originally, I thought I was experiencing anxiety but I realize now that my thoughts are causing me shame and embarrassment. I have done a thought download and I have tried to process the emotions but we have a meeting about this in the morning and I am struggling to let go of the thoughts and therefore the feelings.

C – Project cost over run
T – As an experienced project manager I should have prevented this
F – Shame
A – Rumination about what I could have done, what I will say in the meeting, the reaction of the other party
R – I continue to feel bad, project still has cost over run

C – Project cost over run
T – I am making this a much bigger deal than it needs to be
F – Embarrassed
A – Thought download, continue to ruminate, continue to worry
R – Result remains unchanged and I still feel bad

I’ve tried to sit with the feelings and process, but I have not succeeded and I am unable to let it go. I want to show up at the meeting calm and prepared but at the moment it’s like a tiny child inside is running around panicking.