Thank you, truly thank you so much for your help. I'm so grateful. I couldn't do anything I tried but it started sneezing a lot consecutively and all of the sudden had some kind of attack

.
For future reference purposes,
Today I tried making a toy for Chimby so it would play, idk if it was a string from the toy or if it was a respiratory problem or something else, all I know is it happened suddenly.
I opened it's beak (this time it was letting me) but I didn't see anything, there wasn't anything dangling from it either).
It was wheezing audibly (literally like the penguin toy from the movie toy story). It would close it's eyes and do as if it was "falling asleep" losing energy. A lot of mucous was coming out of it's beak. It would poop a lot in just a few minutes. It would sneeze at first sporadically and at the end it got very bad and somehow ended up in some kind of epileptic like attack (perhaps lack of oxygen) until it died in seconds
I only had one chick, it was always in my room and in the house and had not been in contact with any other chick since I found it. Last Sunday I let it run outside in my yard for a little bit, we introduced it to out new chihuahua and they had a good calm time (they literally ignored eachother

). Then in Monday it gave us a scare because it was "mouth breathing" but silently. That day it did not eat (it wanted to but could not swallow for some reason). We pray so much, and thanks to BYC we gave it a little bit of water with a few drops of apple cider vinegar and a little garlic powder, then we tried water with some honey for some kind of calories because it was very weak. Finally we gave it some mashed potatoes with olive oil and that worked wonders! It started eating and the next day had more energy than ever (it could fly).
On Tuesday, Wednesday and Today it was fine, running and flying around everywhere.
Like I said, it was always inside.
I have carpet and I would vacum it daily and used baby wipes to clean all it's

. I changed it's water and food daily (2-3 times a day). I had a heat lamp lit up for 3 weeks non stop.
I found it 3 weeks ago under the rain all alone, and quickly adopted it.
It was very energetic and sweet. It would normally follow me everywhere and get so happy to see and be with me (it really thought I was it' mom).