Hi Parrot Lover,
Your Coco is a very sick little bird and needs to be taken to an avian vet immediately! He is showing several signs of illness. Since you do not mention his age, I do not know if the food regurgitation is vomiting or rejection of baby formula, but the fact that his is:
1. Fluffed up, not sitting with feather tight,
2. Listless and not energetic and
3. Sitting with eyes semi-closed or closed (probably sleeping more than normal)
Are three of the major signs of serious illness. The others signs are refusal to eat/drink, labored breathing, runny poops unexplained by diet and staying low in the cage.
Of course, I can't diagnose online, nor could the best vet in the world, since a few tests will be needed to determine the bacteria, fungus, parasite, or other reason for the illness. The right diagnosis is critical in order to get the right medications in the correct amounts. Please do not attempt to give meds yourself from the pet store or from your human medications. Giving the wrong meds in the wrong amounts can do harm instead of good.
To locate a good avian vet near you, visit http://www.aav.org/. You really must get to one today if there is any way possible. Call and let the vet know it is urgent and ask for a work-in appointment.
In the meantime, keep him warm by placing a heating pad over or under a portion of the cage and covering three sides of the cage. Try to keep the temp near 85 degrees.
Be sure he is eating and drinking. If he is not doing either, get some pedialyte and mix it 50/50 with warm water (bottle temperature for baby) and give by eye dropper.
I can not stress how urgent it is to get him to a vet today!! The vet will look for symptoms you may not have listed here such as labored breathing, tick in lungs when breathing, abnormal poops, and can easily run simple tests using swabs of feces and throat and blood work to ensure the right diagnosis.
The links below are for supportive care only until you can get to the vet. Then, follow the vet's orders to the letter. Once your green cheek is well, then learn everything you possibly can about keeping him healthy with a good diet of 35% or less seeds, proper caging, variety of perches, and much more. I strongly suggest reading Winged Wisdom's (www.wingedwisdom.com) and BirdSafe (www.birdsafe.com) to learn all about safety, home hazards, and much more in caring for a conure properly. But right now, he must get to the vet right away.
Caring for Sick Parrot Until Vet Visit: http://www.avianweb.com/sickbirdcare.html
Health Care: http://www.parrothouse.com/hlthcare.html
Winged Wisdom Sick Bird Care: http://birdsnways.com/wisdom/ww15eiv.htm
I hope this helps. I'll be pulling for your little green cheek and saying a birdie-prayer for him. Please be sure the car is the proper temperature before placing him into it -- cooled off if you live in hot area or warmed if you live where it is still cold so he won't get a temperature shock.
If I can help further, please use "reply" after accepting this answer.
Breeder
over 25 years breeding, taming, training parrots.
I'm sorry, I did not realize this was a duplicate post when I responded to your question. I do, however, agree with everything you were told in the post which was not closed. I hope your bird gets better