I agree with everything everyone has said and want to give another vote for the bathing. Darwin gets one daily (he poops in it, so we have a bit of a routine which works for both of us! lol!)
BUT - I would like to add one thing. Darwin is just 8 months (Oct. 10th), too and has been acting the same way. You may have seen my posts about brumation. This might be what is up with your guy too, especially if you live in a northern region. We went to the vet on Friday for a checkup, just in case, and he said that there are so many variables and opinions about letting a bd younger than 1 year old go into brumation, but he did agree on following his lead. So I am. When he begins to wind down, the first basking light goes out. He said just don't let his light source be on for any less than a minimum of 9 hours.
I am not saying that there is not something else going on (that a warm bath and a few days won't cure) but just to ease your mind that it may be another natural occurrence in beardie-land! Darwin has not shed for about 3 weeks, lays tight to his branch, rarely gets his pretty yellow (except when he is in his bath ot on my shoulder), goes up to 2 days without eating and when he does it is only a few crickets or superworms. If I did not know about brumation I would be absolutely sure that he was ill.
So I hope this at least gives you something else to consider and that he is likely OK. Darwin is my first beardie so I am learning along with him
.
lele

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Chameleon Help & Resource Info
0.1 Veiled Chameleon - Luna. She's now hanging from her big jungle gym in the sky
1.0 Beardie - Darwin
0.2 felines - Kyndra and Lita
0.1 African Clawed Frog - Skipper
0.3 Mad. Hissers (2 died ;(
0.1 Chilean Rose Hair Tarantula - Rosa Leigh
0.1 Goliath Bird-Eater Tarantula - Natasha