How can I stop being anxious about past, present and future mistakes?

I think one of the first steps you need to take for the past is to realize and accept that you cannot go back and change anything. It helps me to breathe, think about the mistake I made, and then come up with an idea of how I can come back from it. In the present, it may be a situation you can apologize for. If it involves another individual, I feel the least anxious when I talk it out with that person and come to a conclusion. Overall, when you feel anxious about something, I think most of that uncomfortable feeling comes from not knowing everything you would like to. Not knowing what will happen or not knowing how someone else feels. If you're able to learn about the situation, do it. If not, take a deep breath and know that no matter what happens, you will come out okay in the end.

Mistakes will happen. But most of the time, they're just thoughts ; and thoughts can't hurt you. Once you've accepted that anyone makes mistakes, it will get better. But it is even more important to try and practice staying in the present : as past cannot be changed and future isn't known, all you have is right now. Try practricing mindfulness and remember that the present is where you are always safe. It may also be useful to try and reflect on what is and is not a mistake. Ask yourself : am I being too hard on myself ?