This is my first garden & I've been attacked by the Squash Vine Borer . I recently purchased BT and tried to wrap the stem in foil earlier, but I think they were already in the plant before I wrapped them. I went out this morning to spray BT & pulled back the foil & found a dead borer. I don't know if it died because of the foil or the BT. The plant looks healthy on top, but has suffered damage on the stem, can I save it or should I start over?