Sounds an awful lot like what happened to my Chinese Red Bellied Water Snakes - Sinonatrix annularis.
The first one was swimming around biting itself on the body and tail, and the second one started eating his substrate and swimming sideways like a dying goldfish.
They both had periods of what I guess could only be described as the Stargazing you're all referring to.
Guy at the store said they probably envenomated themselves or each other, but this sounds more likely.
Either way, it is no fun.
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Diego
Diego & Tiffany's Zoo:
SNAKES
4.4 Corn Snakes (Different morphs)
1.0.0 Boa Constrictor
0.1.0 Dumeril's Boa
0.1.0 Tangerine Honduran Milksnake
1.0.0 Honduran Milksnake
0.1.0 Mexican Black Kingsnake
1.1.0 Ball Pythons
0.0.1 Ribbon Snake
0.0.2 Rosy Boas (Mid Baja & Baja)
0.1.0 Pueblan Milksnake
1.2.0 Kenyan Sand Boas
1.0.0 Western Hognose
1.2.0 Solomon Island Boas
1.1.0 Gray Banded Kingsnakes (River Road)
0.0.1 Desert Phase Kingsnake
LIZARDS
1.0.0 Frilled Dragon
3.1.0 Bearded Dragons (2 Normal, 1 RedXGold, 1 Citrus)
0.1.0 Eastern Collared Lizard
0.1.0 Merauke Blue Tongue Skink
1.0.0 Turquoise Sunburst Veiled Chameleon
1.0.3 Leopard Geckos
1.1.0 Yellow Niger Uromastyx