I am sorry Sooty is so unhappy.
Hyperthyroid can cause his symptoms:
Older cats experience confusion but it is usually related to hearing or other sensory loss.When an older cat begins howling at night it is almost always associated with hearing loss. The cat is not totally deaf but his hearing is reduced and his own voice sounds so DIFFERENT to him he will go around howling so he can test the tonal quality of his voice much like hearing impaired humans speak loudly or nasal.
There are several things you can do. Play a radio softly at night so he does not "hear" so much quiet. Leave a soft light on so he does not "see" so much darkness. Get some feliway plugins as these will calm him down, he can get very anxious at night. You can get them at some pet supplies or http://www.catfaeries.com/
Older cats suffer from other deminished senses as well. Loss of sight, smell and hearing can cause confusion and disorientation. This is quite disturbing to your baby Kitty dementia is quite common at this age too.
There are vet scripted drugs like anapril that can be very helpful for dementia but.you want to try homeopaths first, get rescue remedy at a pet supply or products at:
Feed him a canned food meal with turkey as it contains l-triptophan and is sleep inducing.Add one mg of melatonin to manage his sleep cycles.
Please let me know how he is doing .
Please be so kind as to rate my answer with positive feedback; that is the only way I receive credit for my assistance. Thank you very much!
Providing a positive rating will not end our conversation, should you need me for any follow-up. Simply click 'Reply' for clarification or additional information, if needed, at no additional charge.