Why Tomatoes, Why???

My tomatoes keep dropping flowers.  According to my coworker, they do this when nighttime temperatures reach below 50 degrees fahrenheit, but it hasn't been that cold.  Perhaps it is a lack of sunlight?  This is what it looks like:

 All crunchy and droppy

She also says that she has a ton of medium-sized green tomatoes on her plants... I have only 5 tiny ones.  Some of my plants are HUGE though!  Check out this current view of the raised beds.

"Mr. Stripey" in the back is definitely a monster. 

Ironically, it is the smallest, weakest looking tomato plant that has the only fruit which is beginning to ripen.  It may be because it's in the clay pot, which warms the roots more and dries out faster... perhaps the plant is in its death throes, trying to reproduce in its last moments?

 

A bit pathetic, yet edible.

As of tonight, I will start spraying the flowers with Blossom Set in hopes that they will stay... it's a hormone that should override the plants' desires to drop flowers in the cold and wait for warmer times.  It's my first year living in this area, but I have a feeling that it won't get too much warmer than this (isn't it summer yet?).  Help me Blossom Set, you're my only hope for ripe delicious summer tomatoes!

How are your tomatoes doing this year, and do you  have any advice for me?