I've worked at Walmart, Ross (discount clothing store), Kohl's, and Toys R Us. Retail jobs SUCK. I currently work at McDonald's, and I'd gladly stay working there as long as I don't have to work in retail again. You think fast food is bad, retail is a million times more horrible. The worst customer you get at fast food is not getting their food the way they ordered, and that's laughable because seriously who screams at someone because they messed up their burger? In retail it's a huge nightmare. Tons of a-hole people. At Walmart I was so stressed out I threw up once or twice a day at work just so I could go home. I also threw up at Ross from the stress.

Seriously, fast food is such an easy job. Retail is hell.

Also, it sounds like you aren't confident enough in your interviews and not knowing what to say when they ask questions. You may not get the job because you've been fired twice, that looks really bad in resumes and interviews.