What filter reduction is necessary for constant exposure?

I'm having the issue where I want to rule out exposure to covid in my room, despite other people in the house at some point being infectious for a couple days before testing. - I was able to install a Merv14 Filtrete in our Hvac system, after despairing over the apparent 3000 cad$+ of upgrading that filter any further (even if I could afford the area of higher filter medium required to not block a normal fan, I guess the system setup is just that pricey somehow, am resigned to it..). But that's for whole house, and I have tried today a IQair Atem desk... I guess because the filter is so strong the max wind current is much weaker then I imagined with covid in mind. This realization is a problem with winter making it increasingly more destructive to need my window open. So that's the backstory.

This is what I have on my mind:
- Wondering if any single filter Merv16 system is enough. This one has an upsetting max CFM of 36... apparently 'just enough for a room(150sqft)', well, that's hard to understand with it being weaker than the output of the room's air vent?
- So then if we are talking about high CFM lower Merv filters... I can see the logic of multiple 80% reductions + the distance traveled in between having some effect, but the time factor of this reduced exposure in an at home situation makes me unsure?
- How can I ever talk to the other people in my house without my filter being portable... Even while wearing a mask (unicorn + fixthemask btw..) just any kind of leakage during an extended conversation feels sketchy. Realize that kind of thought is pushing it to include but I mean too much viral load on top of that would make it worse, so? am unsure there too!
Figured this was enough of a climax of the journey as to include here. What do you all here say about this? let us know in the comments