Are tomatoes fruits?

My tomato plant has seen better days.  I am not sure of what days exactly.  Possibly the first few days after planting and since then it’s been on a slow decline.  At the beginning of the summer, we experienced several heavy rains.  The air was pretty humid and damp and I was worried that the plant was getting too much water.  However, it seemed to recover as the summer days progressed.  Things seemed to be going fine and my little bush plant sprouted a couple of juicy green tomatoes.  Sadly, an unscrupulous squirrel gnawed on the two defenseless tomatoes and the plant never seemed to recover.  In all seriousness I believe that the plant has some kind of disease or possibly the soil lacks sufficient nutrients.  I have planted tomatoes in this container for the past 3 years and although I added fertilizer to the soil, it may have not been enough.  So this is the state of my tomato plant as of last week.  Looks might raggedy right?  I decided to do some research on what went wrong and I cam across a pretty cool resource site – Grow Garden Tomatoes.  It lists several common issues that arise with tomato plants.  I like this site because it is not too technical.  Several    agricultural colleges provide info on plant diseases but I have a hard time understanding them. Way too much Latin.  This site is great and it has tons of information on growing tomatoes.