Hey thank you so much for your kind and thoughtful responses. Just to clarify, I've been in therapy about two years, the tax problem is a little older.
Thanks for the suggestion about hiring a third party. I think I'll try to get on that today. It would be a huge relief to put all this in the hands of a competent person. Of course it's hard to get over my worry about being judged by them, even as I realize they likely see this all the time and I'm not at the centre of their universe but I think finally my freaking out about looming deadlines is worse than my fear that they'll judge me.
Your support is really helpful!