Hello, my name is***** and I have over 20 years of experience as a veterinarian. I understand that you are somewhat puzzled by Gus Gus's behavior and of course would like to avoid any further episodes.
He does sound extremely attached to you.
His face rubbing on you after work is actually a way of marking you as his. Cats have scent glands on their chin and face. They mark their home territory and and sometimes other well beloved "friend cats" by rubbing their faces on them.
In Gus Gus's case he came to you as a young kitten, not having a chance to spend his last critical weeks learning social behavior and establishing his self confidence by interacting with mom and siblings. This sometimes leads to immaturity, insecurity and an abnormally highly attached adult cat.
Your clothes smelled much differently then they normally do, probably with scents he did not recognize as familiar, other than yours, and his marking behavior was an attempt to make sure everyone knows you belong to him.
Also his increased anxiety could have led to a bout of idiopathic interstitial cystitis, painful inflammation of the lower urinary tract, and subsequent inappropriate urination.
Interstitial cystitis is an inflammation of the bladder wall that we think is worsened by stress. The primary condition we are having trouble pinning down.
We do know in these cats however that the mucous layer that protects the bladder wall from urine (which is a mucous membrane irritant) seems to be faulty. So glucosaminoglycans (like adequan) are postulated to help as they are a building block for this mucous. It isn't something that the drug companies can advertise or label the drug for as they would need to do extended testing and trials and there simply aren't enough cats affected to make this worthwhile for them. This is something we do for these cats as we have some anecdotal evidence (reports from other veterinarians that have tried it) that it works. You can give him oral glucosamine supplements like Cosequin.
Omega 3 fatty acids are natural anti-inflammatories that are important for healing and mucous membrane and skin health. I recommend an omega 3 fatty acid dose based upon the EPA portion (eicosapentanoic acid) of the supplement as if we do that the rest of the supplement will be properly balanced. Give him 20mg of EPA per pound of body weight per day. For example an 8 pound kitty could take 160mg of EPA per day.
Omega 3's and glucosamine/chondroitins can work synergistically and improve bladder wall health as well as reducing inflammation. They can take several weeks to see full improvement but some cats do very well with them alone. They are available over the counter.
Likewise we know that by decreasing stress these cats do better and have less episodes in the long run.
Encouraging play behavior and exercise is a natural way to relieve stress. Fishing line toys for him to chase, hiding treats for him to "hunt down" in cat trees or kitty condos can be fun for him too. Perhaps building an outdoor enclosure on a patio or porch so he can go out safely would help.
I recommend Feliway too as a stress reliever. This is a synthetic analog of a calming pheromone that cats use to mark things as safe or home. You can also use a homeopathic medication called Rescue Remedy drops that can be added to his food or water along with Feliway.
Zylkene is another supplement that may help relieve his stress and thus decrease his symptoms. Here is a link if you'd like to read more about it: http://vetoquinolusa.com/Products/Behavior/index.html
Amitriptyline or fluoxetine are prescription medications that are very good at relieving anxiety in some cats, so we can use one of these medications well if supplements aren't enough.
Increasing water consumption helps by diluting the urine, thus decreasing its irritant effects. You should feed him primarily canned food, and add chicken broth or warm water to increase fluid intake further. Kitty drinking fountains can be very beneficial to get him to drink more. He may play in the water, so I recommend putting it on a water proof matt. I know this is messy but play relieves stress too, so I would let him play in it.
I can tell you I have one patient that did very well for a number of years on amitriptyline, glucosamine/chondroitins and omega 3 fatty acids. The owners reported that she was a new cat on this regimen.
If your fellow isn't neutered yet he should be. Intact male cats are much more likely to mark things.
Ideally he would see a veterinarian and have some testing done to make sure there isn't an infection or hidden calculi or crystals in his urinary tract behind his symptoms. Those things should be ruled out first.
In some cases though we are left with a stress driven illness and then we must do our best to change things and relieve stress.
Please let me know if you have any further questions.