help ASAP!!!!!!!!!

ok so i fed my plants a small dose of miracle grow tomato food. it was three tea spoons mixed with 1 gallon of water. the medium i use is also miracle grow soil. i hesitated giving them the nutes but i did any ways and now i think i regret it because there were very little yellowing two days ago and i thought i might of just got it on the leaf. but today there is mad yellowing occurring and i dont think im going to like it. i understand the flushing method but do you think its to late? with this much happening should i ride it out and see if it will prevail or flush them out?

im going to assume that they have chemical burn but feel free to correct me if im wrong. i feel this needs taken care of tonight if i need to flush. if i do need to flush, for how long??

here are some pics!

Feed them only water for a couple waterings...what is all that white stuff on the soil??

the white stuff is diamatasious earth. i had a few gnats and some one recommended this. i highly recommend this to anyone with gnat problems. or soil pests for that matter. it was very effective.

i just gave them regular water today. just as a regular feeding. no flushing.
how far up the plant would be a tell tale sign its a goner??