I am not a pro but I do my lawn nicely. I like nice curb appeal
Not sure I understand your post. Grub is a BUG and you typically want to kill these grub because they eat the grass roots thus killing off the grass. Applying grub killer (there are different brands at Home Depot or Lowes) will kill grubs but best to apply when they are active and growing...thus eating the roots of grass. How can you have grub damage...that is what you want to do damage the grub.
You applied weed and feed. I would have applied turfgrass with crabgrass preventer FIRST. Wait 5 or 6 weeks and do the weed and feed. But since we have had so much rain in my area it has about dissolved the grabgrass preventer and the weeds are ACTIVE now...so I may do the weed and feed in a week or two.
Your detaching is okay to me. If you have alot of thatch, then that is the thing to do. I normally get a thatching rake and only do the areas that have visible heavy thatching. I bag my grass so not al,ot of thatching on my yard. Not sure how dethatching can "rip up thr grub damage" because the grub should be dead anyways so if thatching brings it up to the top of the grass that is fine its dead
If you applied Grub-Ex that is fine. Its supposed to be applied when the grubs are there and actively moving/eating etc. So you did it right. If they were brought to the top...they will bore back down the ground because that is where their food are...the grass roots. Typically grub control like Grub-Ex can be applied anytime of the year and I apply them at the end of May or first week of June to ensure the widest kill of grub. You should be fine and you can find out if you have grubs alove. When I dig up the irrigation rotors to replace them or plant stuff...I usually can tell if I have grub or not. If your grass becomes brown/tan then that usually means grub damage but not always if you have grass fungus.
BTW...I hope you applied the weed and feed stuff when the grass was wet so the granules attach to the weed and after a couple days kill the weed.
Relax and see how it turns out. TruGreen prolly did not kill your lawn but you can apply Grub-EX yourself and save some $$$.