I bought a pretty amazing HEPA filter air purifier for my home when we have company. I can’t remember the brand name, maybe AirBlue? Anyway, each one handles like an 800 sq ft area with normal height ceilings, changing the air out like 20x per hour. Dont’ quote these numbers, please do your own research, but it’s easy to research. I would think even a smaller one would be very helpful in your desk area. Filtration is incredibly effective and should give you a lot of mental relief. Perhaps your building ALREADY has great ventilation/filtration, but bringing your own HEPA filter will give you added comfort.
Getting your 4th shot should also provide an extra level of comfort.
And doing some analysis of the latest statistics will probably also provide comfort. The case fatality rate continues to plummet. And the percent of hospitalized people who are in the ICU due to covid is by far the lowest its been in 2.5 years. Looking into how things have changed/improved over time may provide you some relief.
If you have severe health issues, perhaps you are eligible for EvuShield?
I would also be ready with frequent rapid testing at home and a plan to get a therapeutic if you turn positive (without obsessively worrying about it; just have a plan).
N95 masks are pretty amazing. Think of all of the doctors/HCWs who knowingly deal with people, close-up, touching them, with highly contagious diseases, and are protected with their good quality masks. You could consider doing something to make sure that yours are well-fitting.
I think it’s reasonable to take precautions and then allow yourself to not be too worried. Of course I don’t know what your health conditions are and if they are extreme. But I have several friends on chemo who have had no problem shaking off Omicron, which gives me comfort that it really is getting less virulent. I think doing your own research to the real numbers on case fatality rates and other statistics is likely to make you feel BETTER, and safer, not worse. Good luck back at work; try to enjoy the added sociability! Best!!