Hello, and welcome.
I'm so sorry to hear that Waffle is not feeling well. His hiding, hissing at you and cries when you attempt to move him, all point to a cat in pain.
There are various causes for his discomfort, but with a male cat, what comes to mind first, is a urethral blockage, unless you've seen him urinate normally, within the last 12 hours. When a cat develops a urethral blockage, there is a 'plug', typically of 'crystals' (tiny, sand-like particles) that do not allow the urine to pass out of his body. This is very dangerous, because his bladder can burst and/or his waste can build up in his body, making him sick. Here is more information:
It's also possible that he is severely constipated and can't get rid of his stool without help from the vet. This typically happens when fur from self-grooming and hard, dry stool, form a big mass in his intestines and won't move out on its own.
It's also possible that he jumped down from a height and injured himself, on his paw, leg, thigh, or back and this is hurting him.
Older cats are more prone to develop certain medical conditions, like diabetes, hyperthyroidism, liver and kidney issues, so your next best step, would be to have him evaluated in person by an ER vet to get a diagnosis and then have him treated, so he's feeling much better.
Because these symptoms came on suddenly and there are so many possibilities for them, this is not something that can be treated at home, and that's why I'm recommending a vet visit, asap.
I hope all will be well with Waffle and please let me know how he's doing and what the vet's findings are. Thanks!
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