I know its crazy scary and emet inducing, if it makes you feel better I made it through my brothers being sick a fair amount as a teen and honestly never got sick from their bug. Just wash hands like crazy, if you can use lysol spray everything down before use, and if no lysol use a bleach/water solution to sanitize surfaces etc. Other than that you're doing well with the precautions you've taken already!! I would always kind of avoid sickies by staying in my room. Would make sure I didn't go into bathroom within 20 mins of sicky, more cuz I felt better than any scientific reasoning about how long it takes for airborne particles to settle.

The good news is this will be over soon. These things never last very long and life will go on. Take deep breaths and distract yourself (music with headphones/ear buds) and you'll get through!!