Since the Squash Vine Borer and Squash Bugs overwinter in the soil control starts in the fall with good cleanup and then in the spring by not planting squash family members where others grew last year. Floating Row Covers have proven effective until its time for the blossoms to be pollinated as long as the plants they cover do not have any of these wee buggers in the soil below. Kaolin clay sprays have been shown to be somewhat effective in disguising the plants so they get confused and may not land on the leaves to lay the eggs. Checking the plants for egg masses and removing them can also help. Neem oil products may help but Bacillus thuringiensis - Kurstaki is not very effective, moslty because of timing of application. Perhaps the article linked below will be of some help.
So what are the tomato plants doing?

Here is a link that might be useful: About Squash pests

borers--well that's the interesting thing. last year was the very first year we had this part of the garden AND the very first year i had ever planted squash/zukes. but after a few harvests, they showed up! and i did do the clean up in the fall, and have moved them to another part of the garden this year. thx for the article!

tomatoes---after i put the organic fertilizer in the water and watered them, they looked incredibly wilted which is what i call "ticked off." they were NOT happy about that fertilizer!! and i've tried about 3 different kinds, and they did the same thing. one was a beet based fertilizer. can't remember what the others were. haven't tried fish based i don't think.

hmmmm, well, after looking at the article & pics of the squash borer, i realized that what my squash/zukes had last year was NOT squash borer!!

it was a worm looking bug that actually went into the squash fruit itself and ate the inside. does anyone know what that was? and how to prevent it/get rid of it?

Tomatoes will react that way of the soil is too wet, probably nothing to do with the fertilizer.
You might have had Pickleworms, which can burrow into the fruits.