I think the reason people say it's more for others than yourself is because it's actual pretty rare to catch a disease by breathing it in. Much more often you catch it when it gets on your fingers and then you touch your eyes/nose/mouth. I think that's still at least partially true with covid.
Conversely: pretty much all masks (though ones with an exhalation valve will reduce the effectiveness) will reduce the spread of droplets and thus virus from exhalation and talking: https://www.youtube.com/watch?v=kYJvU81DKgk
That said, N95 masks can work fine if you fit them properly, which may involve shaving any facial hair outside of a mustache, shortening the rubber straps, or adjusting the metal nose bracket.
It’s worth noting that an n95 mask doesn’t really provide vapor protection so it may not do too much for you while you’re painting but if you’re getting wood dust inside then your mask was either improperly fitted or it’s the wrong size for your face.
I've used them while working on-site at a coal mine, as long as you're using a genuine high quality n95 mask and have it properly fitted you can absolutely wear one for 4+ hours without the inside getting contaminated. It's certainly not fun but I've done it many times without issues.
The science of masks hasn't changed...
N95 – Filters at least 95% of airborne particles. Not resistant to oil.
Surgical N95 – A NIOSH-approved N95 respirator that has also been cleared by the Food and Drug Administration (FDA) as a surgical mask.
N99 – Filters at least 99% of airborne particles. Not resistant to oil.
N100 – Filters at least 99.97% of airborne particles. Not resistant to oil.
R95 – Filters at least 95% of airborne particles. Somewhat resistant to oil.
P95 – Filters at least 95% of airborne particles. Strongly resistant to oil.
P99 – Filters at least 99% of airborne particles. Strongly resistant to oil.
P100 – Filters at least 99.97% of airborne particles. Strongly resistant to oil.
I've been wearing a p100 respirator that makes a good seal to protect myself, and been changing out a small piece of cloth on the out-valve to protect others. Please, stop perpetuating the myth that masks don't protect you. Of note is that while many of the higher rated masks tend to be tested at .3 microns, this is often a buffer and real world they tend to filter about .1... and the virus is said to be .12+ micron.
So if you can, I would suggest getting your hands on n100 or p100, preferable use an oximeter to make sure you have the physical fitness needed to force the air through, but if you are doing very small timeframe adventures this becomes less of an issue. Something that makes a good seal is ideal. Guys, you should heavily consider shaving. There is a reason in the military NBC training they started requiring with only a few exceptions, shaves... and no, the military gas masks will not work for this application unless you get the specific filters for this application (if you do, they would be great since they integrate the eyepro), which have a much wider ranger to select from than the above I reference...
note: it is also very important to verify you haven't been sold a fake product
https://www.cdc.gov/niosh/npptl/topics/respirators/disp_part...