I feel dumb asking this, but...

...what do people eat for lunch when they don't like to cook at all? I have some really bad eating habits, and I have also gained weight from that and a medication I was on for awhile. I would like to be more healthy, because my physical state is contributing to these horrible moods I get in. I do like fruits and veggies, but I actually only eat them when they are in the prepared foods I have. Once in awhile I'll have a banana or some watermelon or a nectarine or two. I have looked up "one ingredient lunches" online, but it's never just one ingredient: the wisdom being that it's not a balanced meal. I really love PB&J, but I buy the frozen ones...does that count??? Again, I feel silly, but I could use some advice, for real.