I'm so sorry this is an overwhelming sense of dread and anxiety for you. This sounds like a problem that a lot of people go through, though. So, perhaps knowing that you aren't alone will make you feel better? At least, I think it's common, since I feel the same way. I wonder constantly if I should or shouldn't say something, do something, eat something, constantly. It's like an extreme form of indecisiveness, I guess? It gives me an overwhelming sense of anxiety.
So, I get that it can be quite the struggle.
If you need some help with the anxiety of whether you should or shouldn't, here are some links that really help me when I'm anxious;
9 Ways to Reduce Anxiety Right Here, Right Now | Psych Central
How to Stop Worrying: Self-Help Strategies for Relief from Anxieties, Worries, and Fears
Either way, I hope you feel better soon. Have a wonderful day.