I can totally relate - I always tried to do it all..... and I had to do it perfectly and as fast as I could.
And at the end of the day, I was acutely aware of the things still left undone.
A counselor in rehab once told me I needed to just "be" - He said "We are human beings, not human doings." It's a hard habit to break, though - I'm still working on it.
In the first weeks of sobriety I was able to let a LOT of stuff go, simply because I had to. I saw that when I started thinking about what I needed to do, I got overwhelmed and that made me want to drink. So I just gave myself permission to let things go.
Just my two cents, but I found a couple of things that have really helped me (when I use them!): mindfulness and staying in the moment. There are probably other tools as well, but the big idea is to be aware of what you're thinking and telling yourself that creates the anxiety. Then you can begin to challenge some of those thoughts and begin to replace them with more positive ones.