Sounds a little like last year here. I put a sheet over the tomatoes and watered morning and night, finally got some good maters in the fall.
I also dug up some of the pepper plants and put them in pots, and replanted lettuce and spinach in pots and put them where a tree shaded them all afternoon. Got some produce that way, and brought the pots indoors and continued getting produce during the winter.
Garlic, peppers, tomatoes, spinach, lettuce, rosemary, chives, tarragon parsley, and lavendar was all I got last year.
I guess I should clarify that I used the sheet as a roof to protect from the heat, and create some shade.
A friend of mine in DFW here she tells me that when her tomatoes get all mid summer scraggly from the heat she cuts back on them and waits until the Fall for a 2nd burst of growth. I may rethink my plan of using cuttings and just try to nurse those mater plants via trimmings past August and beyond.
I have a volunteer mater in the tree ring and the others I transplanted to containers but they are slow pokes—but maybe they will be late producers in the Fall if they make it that far. Or if I make it that far, eheheheheheh. Just kidding!