Unlike NIOSH-approved N95s, facemasks are loose-fitting and provide only barrier protection against droplets, including large respiratory particles. No fit testing or seal check is necessary with facemasks. Most facemasks do not effectively filter small particles from the air and do not prevent leakage around the edge of the mask when the user inhales.
The role of facemasks is for patient source control, to prevent contamination of the surrounding area when a person coughs or sneezes. Patients with confirmed or suspected COVID-19 should wear a facemask until they are isolated in a hospital or at home. The patient does not need to wear a facemask while isolated.
~CDC
There are three major problems with facemasks.
1) They accumulate the virus on their surfaces, so that handling them will increase contact, not decrease it.
2) People wearing the masks tend to touch their faces to adjust the things more often, not less, than they would otherwise touch their faces, increasing risk.
3) False sense of security. As previously noted, there was a lot of mask wearing in 1918, but to no evident good effect.
It's not just the CDC that's saying this, either.
And the CDC is not crazy about facemasks for the influenza, either, but their cautionary notes on them are different, suggesting only that if you use them in public you probably need to use them at home, also.
COVID-19 (or SARS-CoV2) is more contagious than the flus have been. It's easier to catch if you are exposed and they find facemasks don't reduce exposure.
Do as you wish. I'm done with this topic.