The best material for a home-made mask is 100% cotton tea towel. Combine that with a filter pocket, make a filter out of a hoover bag to place in filter pocket ( non fibreglass) and it will filter even smaller particles.
Plenty of instructions online on how to make a mask with filter pocket.
You would have to socially distance still, keep washing hands and also throw filter away when home. But you can wash the mask at high temperature and use again with fresh filter in place.
Also make sure you wash hands prior to putting mask on and after taking it off.
Janey