What's wrong with my bearded dragon

[Drogodragon]

Hello I'm worried about my bearded dragon, he has become very lazy recently and is sleeping all the time he very rarely comes out of his hide out and he is very rarely eating, he hadn't pooped for two weeks so I put him in warm water and rubbed his belly and he pooped that was 3 days ago. This morning I checked on him and he had turned a bright yellow colour except under his chin and the end of his tale is black, he had been basking all day long and is ignoring his crickets. I just got him out of my tank to see if he would run around like he used to but he had a poop instead it was very watery and had a big round grey sack in the middle of it can someone please help me I'm extremely worried! He had a few meals worms over Christmas Iv read that they can make them poorly.
I rescued him 6 months ago they said he had just turned 1, he has a lovely 5ft tank he has his Uv strip on throughout the day with his basking bulb on which is at 35c on warmer side of the tank and through the night he has his red night bulb on. He gets fresh veg everyday with his calcium powder on and I change his water bowl daily, I use reptile carpet as I read the sand is bad for them

 

[Canicke]

you're doin ok and he looks really good. he may be going through "brumation" - its hibernation, really. They slow down or stop altogether for several months. My current male will sleep for 2 to 4 days, then be up and around (although not his usual crazy self) and eating and pooping for a few days. and repeat. my last male would go to sleep for MONTHS !!! Like i've noted on another post, my female is a slug so its hard to tell if she's brumating or just being her normal self. The cocooned poop - i've seen it, too. i read about it once, but as i recall, it was of no consequence so i havent worried about it since. If you're super concerned - take him to the vet. i'd bettin on brumation, tho.

 

[Canicke]

something i forgot to mention - i do not recommend the use of any kind of light at night. even the red light can initerfere with their sleep. if you are concerned about the heat at night - get a CHE (ceramic heat emitter) - it provides heat with NO LIGHT If the tank does not get below 65 degrees F, you dont really even need to worry about that.

 

[Hdrydr31]

Yep sounds like he's brumating... Let him do what he wants to do, offer him bugs and greens and if he eats try and make sure he poops before sleeping for an extended time as you don't want it sitting in their belly/gut too long as that can be bad for them.. Once a week take him out and put him in a warm soak (don't leave him unattended in case he doesn't wake up from sleeping , keep his head above water) Do this for 15-20 min to help rehydrate him and help him poop.
Ditto on what Canicke stated..