Boy... you know.... I'm a "senior citizen" now & my parents are both long-since gone. But I got so much of what you described back when they were alive. This whole parental guilting thing really cranks my shaft, to coin a phrase. It's just my personal biased opinion. But I don't think you did anything wrong. And I think your mother not wanting to talk to you is passive-aggressive. And that's not your fault or your responsibility.

So my suggestion here is don't take on the load of guilt your parents want to dump on you. And don't buy into the passive-aggressive dance either. Tell them straight out why it is you didn't call. They can either accept it or not. That's their choice. They're your parents not the other way around. You're not responsible for their feelings. You wrote you should have called. Someone once said: "don't should on yourself." It's good advice.

Here's a link to a brief article, from PC's archives, by DocJohn on the subject of guilt. It provides links to a bunch of additional articles on the subject:

Guilt: Why Do I Feel Guilty? - Psych Central

My best wishes to you...