I know a lot of people are struggling with the heat right now.
Deep shade, shade cloths, cool water, fans, etc. are all ideas I see suggested. I do use fans in my run and coop along with cool water. I don't have the temps like you do in CA but a few of my heavy girls struggle in hot weather too.
The weather sounds terrible!
Here's 2 of the best articles I know of when dealing with crop issues.
https://www.backyardchickens.com/articles/how-to-treat-sour-crop-and-impacted-crop-and-how-to-know-which-one-youre-dealing-with.73607/...
I'm sorry to hear about your injuries, I hope you will have a speedy recovery.
If the photo of your birds that you posted are current, they are still quite young looking to me, but I do see a little bit of pinking up. You may see a difference in them once you limit the scratch and they start...
How old are you chickens?
Yes, I would drastically cut back on the scratch - a mix like that really should be no more than 1 tablespoon for each bird.
I know that some places do mix or mill feed, but personally I would want to see the guaranteed analysis and ingredients. Not all feeds are...
Do you have a photo of the tag on your feed (nutritional analysis) or of the bag?
Scratch is a treat and so is the corn on the cob. Aim for any treats to be no more than 5-10% of their daily intake depending on the protein content of your poultry feed.
I love to give mine a treat too, but 2...
Read back at posts and photos. OP's response is to treat suggestions given by someone. OP does mention giving feed, but pullets are not interested in any other "treats" except for scratch/corn.
Photos looks like there are crumbles/feed available in feeder.
How old is she?
Can you take her to the vet?
The drooling and smelling like vomit sounds like sour crop.
If she is not drinking, then likely she is overheating.
I would get her hydrated, if you have electrolytes those would be good. She need to get drinking before she eats anything...