First, choose the type of zombie you'll be confronting. They can be classic, slow-movers as in the original Night of the Living Dead, or they can move fast, 28 Days Later-style. Are animals affected? Because you'll want to stay away from the wet markets and other places where locals buy live food. Think through the details of the infection. Are you immune only because you haven't been bitten? Or is this a more apocalyptic situation--is there a disease you alone are immune to, in addition to the zombies (a sort of double alien threat you'll eventually have to confront, a la Day of the Triffids)? What kills the zombies? Is it the traditional destroying of the brainstem, and if so, are organs able to live on independently of their bodies if this brain stem remains intact? Do the zombies retreat when it's light outside? Take some time to consider all these possibilities before deciding.
Next, start to plan your immediate escape route. You are in a massive modern hotel with non-opening windows. This is not good. Think through every escape route, every guest, worker, visiting prostitute that might now be wandering the hallways, either livng or zombified. Who will you save? Is it worth checking down the hallway that your mother-in-law has not yet been turned into a zombie? If you call her on the phone, will the ringing of the phone alert the zombies in the hallway to her living presence? The elevators are certainly not safe, but the emeregency stairwells are a deathtrap as well. What would it take to break the windows and crawl along the ledge to mother-in-law's room, and then to make it all the way down to the walkway along the bay? What sort(s) of weapon can be found in a hotel room? Is there any way of making it the eight storeys downstairs to one of the restaurants where more suitable tools could be found? Or is the risk of re-animated abolone, sharks' fins, gigantic lobsters, and night cleaners too great? Consider all of this many times over, and in different ways.
What are your prospects if you escape the hotel? Where will you go? Hong Kong is an isalnd; you are on Kowloon, on the mainland. It makes sense to get across the bay and eventually band together with other living people to clear the island of all zombies, using the surrounding water as a barrier. Of course, this will be a problem if they learn to walk underwater as in the remake of Dawn of the Dead.
As always, the only hope of long-term survival is knowing how to pilot a plane or helicoptor. But this thought doesn't help your insomnia. Instead, re-imagine your escape plan from the hotel to the island, and how you go about hiding from, and disposing of, zombies once there. Keep going. It'll be light out soon.