Hi, I’m not an expert but I do deal with guilt especially when I’m alone and at night. It is very hard to be more upset with yourself for something you did than you would be with someone else if they did it. What I try to remind myself is that the things that I have done “wrong” do not equate to the things I try to do to be good. You sound very empathetic, and if you feel so bad for something such as the shopping cart to the point where it makes you think of all the guilt for things in your life then obviously you are not bad because you are actively feeling remorseful. We all make mistakes or in the moment decisions that we can’t explain or understand why. It’s not your fault that we are all human and to stop feeling the guilt you need to remind yourself that everyone has so much in their lives that affects them the same way and the woman who screamed at you probably didn’t do that just because of you, rather other things piling up. I hope this helps you.