It’s 80°,I will try to get her to drinkHow is the weather and heat? Can you try getting her to drink some water from a lid or small container? She could be dehydrated, although heart failure may be a problem. Chicken feed made wet with water can be good to offer. Can you post any pictures of her and her comb?
She doesn’t have any other physical signs except for the comb, Being somewhat lethargic and her not wanting to get up and she only gulps for air when you try to move her like she’s trying to make some sort of noise and I am not sure when she laid her last egg because she’s in a coop with other chickens and she is a legit Rhode Island Red, she’s five years oldFirst you'll need to physically examine her, every little thing counts from the top of her head to the bottoms of her feet. You'll be looking for injuries, swelling, excessive heat, scabs, external parasites, etc. Examine her face, eyes and nares, anything bubbling or wet? How does her breathing sound? Is she opening/closing her beak, as if gulping air?
When did SHE lay her last egg? How old is she? Is she legit Rhode Island Red or is she a 'production red' bred specifically to lay large eggs and to lay more frequently at the expense of her lifespan. These and the questions asked by @Eggcessive will help to narrow down suspected problems.
I am glad to hear that she's feeling somewhat better. If she were my girl, I'd keep a watchful eye on her. I will keep you and your feathered family in my prayers.I have given her normal water and sugar water, she is balancing herself on her own instead of just laying over on her side and she is eating and drinking by herself now