serious work problem?

I worked at a grocery store for 2 years, and I quit without any notice, because of some issues with my managers and co workers. then, I got a job at a restaurant as a hostess and I couldnt handle it. I worked there for a week and I was having a hard time with it. I lost sleep and literally made myself sick thinking about going there. I had an anxiety attack the last time I worked and basically quit on the spot because I couldnt handle it.
I have an interview friday at macys and I was feeling pretty confident about it, yet now I just quit my current job and I dont want to look bad. how should I go about talking about that?
I need this job and I am pretty good at interviews but when It comes to this I am lost.
please help.